Max Wedge heads

[Voss]

I pulled the valve covers (six bolts) from my -68 R/T today (I got the car home last week) to check the casting numbers and date codes.

The casting number seems to be 2408518, couldn't figure out any casting date yet. It is a bit difficult to see if it's "8" or "6" but I'm almost sure I got it right. I don't have my books with me to check the casting numbers...

I must admit I'm not familiar with these heads... I expected 906 or 915 heads on this car. I have plans for the car to restore it back to all original so these heads would probably have to go... Any comments form you guys here? Could it be Max Wedge heads? Any clues on how to identify?

[b5blue]

Mopar B/RB HP Book shows 2406518 as 1964 426 Max Wedge Stage III. 

[tan top]

 



think thats 516 could be just the way i'm looking at it   the pre 68 383 head  , don't know the valve sizes  with out looking it up  
the 518 =  426 max wedge head ,  intake & exhaust ports are too tall i think for stock type 4 barrel intakes &  iron HP exhaust manifolds

but i'm no  expert on this  

[Sublime/Sixpack]

That 7th digit in the photo is difficult to make out. If you had the intake manifold off so you could see the size of the head intake ports it would be obvious whether they're the 516's or max wedge 518's.

[histoy]

Max Wedge heads do not have the heat crossover passage in the center.  The head pictured has it, so this is not a Max Wedge head.

[Voss]

Max Wedge heads do not have the heat crossover passage in the center.  The head pictured has it, so this is not a Max Wedge head.

I think so too, also noticed the heat crossover. I have not checked the numbers again, but I think these are 2406516 heads. Not exactly right for this car since it is a -68 with 440 (D 440 HP). Smaller exhaust valves (1.6) if I'm right. I'm not an expert on cylinder heads, but the correct ones should be 2843906? Is there a difference more than the exhaust valve size? Did all 440's and 383's come with the 906 heads for -68 to -70? I have read somewhere about 2951250... From what I can understand the 906 and 250 heads have identical valve sizes so what's the difference?  

Hmm, by the way, are the heads identical on left and right side? The same casting numbers? What would be a fair price for a pair of date correct 906 heads (in decent condition) you think? I am looking to replace them to get things right...

[Chryco Psycho]

I thought the Max heads used the 4 bolt covers too ?

[404NOTFOUND]

Sorry to bring you the bad news but, those are indeed 1966-1967 vintage 516 heads. They are closed chamber, high compression heads with small 1.60 exhaust valves and small ports. Perfect for those who enjoy detonation on today's cheap pump gas and not much horsepower. Pictured below are my 516s that I pulled off of my 1966 440 that are now rusting away in my back yard awaiting a trip to the scrapyard. Notice how the number 2 in the casting is crooked on both our heads. If my casting numbers look a bit funny it is because it is raining right now when I took the picture. Is your car matching numbers? An early '68 car built in '67? Not sure if that could have happened.

[histoy]

Max Wedge heads used 4 bolt covers for 1962 & 1963.  In 1964 they had 6 bolt covers.

[b5blue]

  Again the book: "1968-71 383-440 #2843906". Your head (#2406516) 1964-67 361-383, 1.60" ex. valve. Not relevant to your situation but book shows 1963-64 as first production of cast in rocker shaft stands and 6 bolt valve covers.
  I've found lightly rubbing the cast #'s with emery paper highlights the digits nicely. 

[404NOTFOUND]

Another thing to consider is that your heads are painted blue and it looks like they were painted with the valve covers installed indicating engine work may have been done at some point. I'm not sure how the factory normally paints the engines but, I do know that the 1966 440s were painted red or at least some of them were. My heads were painted red everywhere on the castings under the valve covers. Can anyone shed some light on this? Was engine painting always done a certain way at the factory or did it it vary from year to year etc?

[Voss]

  Again the book: "1968-71 383-440 #2843906". Your head (#2406516) 1964-67 361-383, 1.60" ex. valve. Not relevant to your situation but book shows 1963-64 as first production of cast in rocker shaft stands and 6 bolt valve covers.
  I've found lightly rubbing the cast #'s with emery paper highlights the digits nicely. 

Thanks for the tip with the paper, I will try that. Agree with you on the numbers, I checked the head castings in Galens books and I got to the same conclusion.

[Voss]

Another thing to consider is that your heads are painted blue and it looks like they were painted with the valve covers installed indicating engine work may have been done at some point. I'm not sure how the factory normally paints the engines but, I do know that the 1966 440s were painted red or at least some of them were. My heads were painted red everywhere on the castings under the valve covers. Can anyone shed some light on this? Was engine painting always done a certain way at the factory or did it it vary from year to year etc?

The car is what I believe numbers matching. It has the partial VIN stamped at the block/trans and the casting number of the block is correct as well as the date considering the engine assembly date. I also checked the machined pad at the front of intake and the PT440... at the bottom and it matches with the block type and engine assembly date. Trans numbers are good to. The trunk lip and rad support matches the fender tag so... The only thing I have not recovered is the build sheet...

I know the engine paint is not correct. It should be turquoise. The paint they used is to "blue". And I have seen other signs which tells that some engine work has been done, at some point in time. New gaskets, wiring and so on... Not too long ago I would guess. So... In a weak moment someone did replace the heads, too bad for me. Seems like crappy heads to use on a 440, yes?!  I will call the previous owner and see if he might have some clues, but it would be a long shot... However, it should be fairly possible to find a set of good 906 heads with a date code which is reasonable? I'm looking to restore this car in detail, so original heads with proper date codes are a must...

[404NOTFOUND]

It's possible that someone thought the "high compression heads" were better without realizing the ports and valves were smaller. In your case, I would look for some 906s ported or not. Lots around cheap nowadays as guys like me with non matching cars switch to aluminum heads.

[Chryco Psycho]

it is also possible that the heads were machined & had hard seats & 1.81 valves installed which I always did when I used the 516 heads

[Challenger340]

If the Engine was rebuilt at some point in it's earlier history ??

Shot in the dark here.....as to what "may" have transpired in the past....

It was extremely common back in the day, due to the lack of decent "rebuilder" Pistons, that when these Engines were bored and rebuilt, that VERY low compression replacement Pistons were used......even though they were advertised in error as " 10:1" for the 68/69 Engines with 906 Heads... they were NOT !
They ended up more like high 7's to 1 on the 906 Heads.
hence...after rebuilding....
When people found out their "Rebuilt" 440 Magnums were TERRIBLE terds powerwise....from the low compression....
Guys would try swapping Heads and utilizing the closed chamber 2406516 heads after rebuilding(instead of the original 2843906 open chambers), as a way to try and bump the Compression back up.....
and restore some " performance" that was lost, from the extremely LOW compression after rebuild with the lowsy slugs of the day....

Might be adviseable to CHECK what Pistons are in the Engine, BEFORE swapping on the open Chamber 906's in place of the incorrect 516's ??
hence,
you may not be real happy with the "performance" afterwards ?

IMO,
Whats the point being "numbers" correct with the 906's, if it means being totally performance "retarded" as a result of the 7:1 C.R. ?

The BAD pistons are easily spotted when a Head is removed, as they are about .100" down hole at TDC.

The other way to predict a "probably" Piston present...WITHOUT removing the Heads....
How does the Engine run right now ?   ...any "pinging" etc currently on Pump Fuel ?

Absolutely no doubt about it...HIGHLY doubtful..... that if it still has the "correct" High Comp 68/69 440 Magnum Pistons still in it.....it would probably PING pretty good on todays pump fuels with any timing in it at all, using a 2406516 closed chamber head.....because of too high compression.
IMO,
if it's currently NOT pinging, and currently running fine with the 2406516 Heads on Todays crap fuel, then it's probably been rebuilt at some point earlier with low-pop slugs, and the 516's are best left alone, than swapping to the 906's and a noticeable performance LOSS.

I hope this is NOT the case, I do not wish to be the bearer of bad news regarding your Engine, just pointing out something to check FIRST, before spending lots of $$ to find out what has been common for others in the past,
and,
the most probably reason behind "WHY", the incorrect 1966 2406516 castings are in place currently, on your 1968 2843906 "magnum" Engine.

[b5blue]

Good point and 100% correct!
  My stock 69 block 440 had a hugely worked set of those heads and a 509 cam when I bought the car. The stock dizzy had been re-worked, the heads nicely max ported to the TM-7 intake and headers with oversize exhaust valves also. Adding the six-pack to that setup even prior to today's crap fuel the engine was very fussy about fuel and tuning. It took all I could do to keep the ping out.

[Cooter]

FYI here, but I beg to differ on the "516" head not making much HP or Detonation prone. There is only about 10 CFM difference between box stock "906" and "516"/"915" heads on the flow bench. Ported, they perform very nice.

I would run those before I lowered the compression a full point with open chamber heads.

Anybody want to lose a set of GOOD "516"/"915" heads, lemme know...

[Troy]

I have a set of 516 heads on a 68 440 HP that I bought a while back. I heard from others that it ran really strong when they had seen it around. I had assumed the previous owner installed them for the bump in compression. I have no idea if the valves were changed as the engine hasn't been apart since I got it.

Cooter I'll probably get rid of these when I put the correct 906s back on (it's going in my 4-speed R/T).

Troy

[b5blue]

FYI here, but I beg to differ on the "516" head not making much HP or Detonation prone. There is only about 10 CFM difference between box stock "906" and "516"/"915" heads on the flow bench. Ported, they perform very nice.

I would run those before I lowered the compression a full point with open chamber heads.

Anybody want to lose a set of GOOD "516"/"915" heads, lemme know...

Don't get me wrong...the car ran like a raped ape! When I dropped them on the counter @ Clearwater Cylinder Head Inc. the guy's jaw about hit the counter! I gave them back to Chuck for his race car as he was helping me re-work the block. (He's the one who did all the work on them.)

[Challenger340]

just some trivia about Intake ports....although no body asked, it might clarify some things about the different early Iron Head Castings

1964-1966 2406516...Closed Chamber, 2.08"/1.60" Valves, low floor FLAT Intake Port, no Siamesed Hump in Port wall.

1967 only 2780915...Closed chamber, 2.08"/1.60" Valves(except HP version in '67 GTX with larger 1.74" exhaust from factory), "HUBER" Humped HIGH Floor Intake Port which is IDENTICAL to the 284906 Head.

1968-1970 2843906....Open chamber, 2.08"/1.74" Valves ALL, "Huber" Humped HIGH Floor Intake Port originally introduced on the earlier 2780915 closed chamber '67 head.
(it is generally thought, that this is the reason that back in the Day when the '68-'70 383 "magnums" were introduced, that it was a 383 "with 440 Heads" story was floating around... because of the '67 HIGH port Floor 915 Heads Intake port being used on the open chamber 906 Heads installed on the wee-83's)

1970's 346/452 Heads.....open chamber, 2.08"/1.74" Valves ALL, low floor FLAT Intake Port, however, addition of the "hump" on the siamesed Port wall directly behind the head Bolt Hole in front of the Bowl, which enhanced swirl and Flow on the low port.

3 basic "families" of Intake Ports outside of Maxi's
516...and some earlier production
915/906
346/452
From a Flow standpoint, they can ALL support over 500 hp with minimal work, WITH the 1.74" exhaust valve, so it doesn't matter which one is chosen for all but the most ardent & serious applications....

 

[Voss]

Many thanks for all the info and hints in this thread. I must say this forum is really great!  

I'm currently using premium 98 pump gas (95 is regular fuel here in Sweden, but I use premium 98). I have not observed any pinging, but I have just got the car and only driven it a few miles. The engine runs strong and fires right up (even in cold weather as it is here now). So there are really no issues with the engine. The guys who done the rebuild seems to have done a good job.

I won't tear down the engine at this point. However, I aim to restore things back to original on this car so I want the 906 heads since they are after all what supposed to be there. But I will try to figure out what's done to the internals of this engine before doing any rebuilds back to original. What Challenger340 posted about the pistons is very interesting (btw, thanks for all your info)... I will definitely check that out when I remove the heads next winter.

I will do a compression test next weekend when I'm at the car... What would be the expected psi reading assuming original pistons and original 516 heads? And what would the psi reading be for original pistons and original 906 heads (all original 440)? I'm trying to figure out if I can use the compression readings to understand what's done to the engine without tearing it down...

/Andreas

[Challenger340]

Many thanks for all the info and hints in this thread. I must say this forum is really great!  

I'm currently using premium 98 pump gas (95 is regular fuel here in Sweden, but I use premium 98). I have not observed any pinging, but I have just got the car and only driven it a few miles. The engine runs strong and fires right up (even in cold weather as it is here now). So there are really no issues with the engine. The guys who done the rebuild seems to have done a good job.

I won't tear down the engine at this point. However, I aim to restore things back to original on this car so I want the 906 heads since they are after all what supposed to be there. But I will try to figure out what's done to the internals of this engine before doing any rebuilds back to original. What Challenger340 posted about the pistons is very interesting (btw, thanks for all your info)... I will definitely check that out when I remove the heads next winter.

I will do a compression test next weekend when I'm at the car... What would be the expected psi reading assuming original pistons and original 516 heads? And what would the psi reading be for original pistons and original 906 heads (all original 440)? I'm trying to figure out if I can use the compression readings to understand what's done to the engine without tearing it down...

/Andreas

Trying to guess an accurate Static Compression Ratio, from a Compression psi or "effective" pressure, is not a very accurate method to determine Pistons present ?
Very hard to guess a compression reading without knowing the Camshaft events ?
How big is the Cam ? Overlap ?
How well is the Engine sealing ?
What Compression method ? ..4 Bumps...1st bump 75% of the 4th and final bump ?
too many variables to doing it right here......

If your intent is to have the 906 Heads at all costs for Vehicle number legitimacy, IMO, PULL the Heads and LOOK at the Piston heights to be sure.

[b5blue]

I believe the 346/452 heads are 1.74 exh. valves like the 906's.

[Challenger340]

I believe the 346/452 heads are 1.74 exh. valves like the 906's.

yep your RIGHT...me bad...dunno how that typo happened...thx !

[Voss]

Many thanks for all the info and hints in this thread. I must say this forum is really great!  

I'm currently using premium 98 pump gas (95 is regular fuel here in Sweden, but I use premium 98). I have not observed any pinging, but I have just got the car and only driven it a few miles. The engine runs strong and fires right up (even in cold weather as it is here now). So there are really no issues with the engine. The guys who done the rebuild seems to have done a good job.

I won't tear down the engine at this point. However, I aim to restore things back to original on this car so I want the 906 heads since they are after all what supposed to be there. But I will try to figure out what's done to the internals of this engine before doing any rebuilds back to original. What Challenger340 posted about the pistons is very interesting (btw, thanks for all your info)... I will definitely check that out when I remove the heads next winter.

I will do a compression test next weekend when I'm at the car... What would be the expected psi reading assuming original pistons and original 516 heads? And what would the psi reading be for original pistons and original 906 heads (all original 440)? I'm trying to figure out if I can use the compression readings to understand what's done to the engine without tearing it down...

/Andreas

Trying to guess an accurate Static Compression Ratio, from a Compression psi or "effective" pressure, is not a very accurate method to determine Pistons present ?
Very hard to guess a compression reading without knowing the Camshaft events ?
How big is the Cam ? Overlap ?
How well is the Engine sealing ?
What Compression method ? ..4 Bumps...1st bump 75% of the 4th and final bump ?
too many variables to doing it right here......

If your intent is to have the 906 Heads at all costs for Vehicle number legitimacy, IMO, PULL the Heads and LOOK at the Piston heights to be sure.

Thanks for the info, now what you are saying makes perfect sense... A static compression reading won't tell that much about the internals, agree on that...   Besides measuring, is it possible to identify the pistons by any numbers/marking or something like that? And what would the measurement down hole at TDC be for a stock engine (to have 10:1 C.R. with stock cam and pistons)?

[Challenger340]

The Factory original '68 to '70 Pistons(non 6 Pack)..... from memory were about .060" Downhole,
however.....
that was WITH using a Steel Shim Head Gasket @ .022" thick.

The factory used to advertise the Comp Ratio as 10.1:1 for the above Pistons, and it would have been, based upon a Ma'Mopar "published" Volume for the 2843906 open chamber head as 79.5 CC,
which,
because of the HEMI's DOMINATION of the Super stocks ranks...
... was quickly adopted by NHRA, and other Drag Race sanctioning bodies of the period, as "Legal" minimum sizing on the Magnum Wedges.

In the REAL World However,
Because most of the 906 Heads of the time, came in around 82-84 CC's as produced with no Valve seat recession, actual Compression from factory on the Engines "as delivered" was only around 9.8 to 9.9:1 using the steel shim Head Gasket.

Anyways, and back to your question.....
Simply reproducing that .060" Piston downhole @ TDC these days, will NOT necessarily duplicate that Compression Ratio, or the Performance, due to variances in 40 year old 906 heads, and the lack of Steel Shim Head Gaskets(dunno if still around..or if you wanna use them anyways), and changes in Engine Swept CC Volume with Boring & Honing Cylinder Oversizes.
Long Story Short.....
You would need to BLUEPRINT your Engine.....and 906 Heads...Camshaft...etc., etc.

The GOOD news..
is that if you do undertake Blueprinting back to factory specs, on a SuperFlow 902 Engine DYNO with minor Head work, these Engines WILL produce around 400hp/500Trq using stock manifolds and 2 1/4" exhaust.....
I can pm you Dyno Sheets from my Shop as proof( the last 6-pack example we did churned 425hp and 530Trq using Flat Tappet Repro Cam !)

I applaud your efforts in this area, to RESTORE not just the Car, but the factory PERFORMANCE as well.....
I will Not mince words here...
I find it an absolute SHAME, that far too many "restored" numbers matching Musclecars.....are absolute TERDS once the loud pedal is mashed due to the owners lack of continuity & diligence in the Engine Dept.
I'm OLD...... I DROVE these things.... and RACED them....back when still fairly "factory" and "untouched".....so I dunno whether to LAUGH or CRY sometimes with some of the "award winning" restored Cars I've seen these days.....some can't get outa their own way.

[BSB67]

Many thanks for all the info and hints in this thread. I must say this forum is really great!  

I'm currently using premium 98 pump gas (95 is regular fuel here in Sweden, but I use premium 98). I have not observed any pinging, but I have just got the car and only driven it a few miles. The engine runs strong and fires right up (even in cold weather as it is here now). So there are really no issues with the engine. The guys who done the rebuild seems to have done a good job.
I won't tear down the engine at this point. However, I aim to restore things back to original on this car so I want the 906 heads since they are after all what supposed to be there. But I will try to figure out what's done to the internals of this engine before doing any rebuilds back to original. What Challenger340 posted about the pistons is very interesting (btw, thanks for all your info)... I will definitely check that out when I remove the heads next winter.

I will do a compression test next weekend when I'm at the car... What would be the expected psi reading assuming original pistons and original 516 heads? And what would the psi reading be for original pistons and original 906 heads (all original 440)? I'm trying to figure out if I can use the compression readings to understand what's done to the engine without tearing it down...

/Andreas

Trying to guess an accurate Static Compression Ratio, from a Compression psi or "effective" pressure, is not a very accurate method to determine Pistons present ?
Very hard to guess a compression reading without knowing the Camshaft events ?
How big is the Cam ? Overlap ?
How well is the Engine sealing ?
What Compression method ? ..4 Bumps...1st bump 75% of the 4th and final bump ?
too many variables to doing it right here......

If your intent is to have the 906 Heads at all costs for Vehicle number legitimacy, IMO, PULL the Heads and LOOK at the Piston heights to be sure.

Thanks for the info, now what you are saying makes perfect sense... A static compression reading won't tell that much about the internals, agree on that...   Besides measuring, is it possible to identify the pistons by any numbers/marking or something like that? And what would the measurement down hole at TDC be for a stock engine (to have 10:1 C.R. with stock cam and pistons)?

Here are the stock replacement piston compression heights used over the years: 2.06, 2.03, 1.99, 1.93.  Generally, these in an uncut block go: .020, .050, .080, and .140 in the hole, respectively.    The 2.06 is the six pac piston, and 2.03 is the 68-69 piston.  The 2.03 piston has not been available new for over 20 years.  Frankly, the 2.03 piston with a 906 head is a poor choice any ways with today's gas. 

I too am a bit embarrassed when the restored car guys hit the track and turn 15's, but that's just me.  The only way my car would win a prize at a car show is if I was the only guy entered.