Which Heads are Better???

[kycarnut]

Once again I must dip into the "WELL OF KNOWLEDGE" that is provided here at dodgecharger.com and lets all be thankful it is. Now for the question  "Which is better the 906 or the 915 heads" Keep in mind I'm  building a mild 440 something with 400-450 HP and not use a high lift cam. Thanks 

[b5blue]

Wedge's do not like the valves sunken and nether has hardened seats so figure on installing them. The 915's are closed chamber (higher compression) so unless your replacing pistons and compensating that way you would end up needing to retard timing so much you'll loose power as pump gas at best is 93 octane. The 906's for a mild build would be more of a "street-able" pick with today's lower octane fuels. Be careful, by the time you install hardened seats, valve guides, do any "bowl work" and replace the valves, springs and keepers you may add up close to the price of a set of Eddy or Mopar Aluminum heads that flow better and handle lower octane fuel due to the heat soak property's of aluminum, along with saving 50 lb. of dead weight for a few bucks more. If the 906's are in great condition this may be the choice but check or have them checked very well before you start spending money. I highly recommend a big block Mopar book be read first so you fully understand what all your choices are before you buy or do anything. Then you can get into exact details with the guys here to have a proven combo just the way you want.  (the 915 would be a good racer set of heads if in good shape and may net you some good bucks as some guys are into high quench set-ups.)   

[RD]

http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/index.html
http://www.moparmusclemagazine.com/techarticles/5118_cylinder_heads_ii/index.html
http://www.moparmusclemagazine.com/techarticles/5120_cylinder_heads_iii/index.html

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0804_cylinder_head_selection/index.html

[b5blue]

YEA! Good Stuff.....now about the block.......

[71383bee]

For 440 since piston availability is much better I would go with the 906's.

If this where a 383/400 hands down 915.  The piston choices are poor and they yield anemic compression on the B blocks so the CC heads help a ton in getting compression up. 

I always heard that the 915 and 906 heads shared very similar port designs...

[firefighter3931]

The 452 heads would be my choice ; hardened exhaust seats and they respond very well to a basic bowl port. Easy 450HP head with 9.5 compression and the right cam/intake/exhaust/carburator. 


Ron

[b5blue]

I'm running 346's bone stock, with a P4452783 (resto) cam and P3690933 springs, it is very street friendly. What cam/carb would you pick for him Ron? 

[kycarnut]

The 452 heads would be my choice ; hardened exhaust seats and they respond very well to a basic bowl port. Easy 450HP head with 9.5 compression and the right cam/intake/exhaust/carburetor.

I have a stock 4 brl. Intake from early 68 and will probably run stock Exhaust Manifolds. I have a Holly 4779 750 Double pumper with Manuel secondaries and I would like to find a cam that has a good torque curve on low end and a power range of maybe 1500 - 5500. I want an engine that will let you know this is a muscle car but not a race car. What would you recommend. Thanks Greg

YEA! Good Stuff.....now about the block.......

I'm trying to find a date coded block from the month of January 1968. My goal is to have a date coded, period correct looking engine, with a little more punch. Thanks Greg

[firefighter3931]

The 452 heads would be my choice ; hardened exhaust seats and they respond very well to a basic bowl port. Easy 450HP head with 9.5 compression and the right cam/intake/exhaust/carburetor.

I have a stock 4 brl. Intake from early 68 and will probably run stock Exhaust Manifolds. I have a Holly 4779 750 Double pumper with Manuel secondaries and I would like to find a cam that has a good torque curve on low end and a power range of maybe 1500 - 5500. I want an engine that will let you know this is a muscle car but not a race car. What would you recommend. Thanks Greg

YEA! Good Stuff.....now about the block.......

I'm trying to find a date coded block from the month of January 1968. My goal is to have a date coded, period correct looking engine, with a little more punch. Thanks Greg

Greg, the factory manifolds complicate things somewhat....they are restrictive and will hurt the power output. What converter and rear end gearing are you planning to run ?



Ron

[b5blue]

Didn't you point out the 70 intake was about as good as factory gets Ron?

[kycarnut]

What converter and rear end gearing are you planning to run ?

I will proably run a 2500 - 2800 Converter and I right now I'm running 3.55 gears in a 741 case.

I was reading this thread earlier do you think it would work for me

^{http://www.dodgecharger.com/forum/index.php/topic,64073.0.html}

Thanks for the Help.

[b5blue]

Heck ya!  Good luck!

[firefighter3931]

Didn't you point out the 70 intake was about as good as factory gets Ron?

Yep, the 70-71 4bbl intake is the Best factory piece. 

What converter and rear end gearing are you planning to run ?

I will proably run a 2500 - 2800 Converter and I right now I'm running 3.55 gears in a 741 case.

I was reading this thread earlier do you think it would work for me

^{http://www.dodgecharger.com/forum/index.php/topic,64073.0.html}

Thanks for the Help.

Sure, that would work but it's not a budget build. Ported heads and hyd roller cam won't be cheap. Properly ported heads could cost more than $1500 fully prepped with all new hardware and figure on another $1500 for the roller cam, roller rockers, bronze distributor gear etc.....It gets expensive in a hurry when you go "Roller" 

Are you wanting to go Hydraulic or solid cam ? How are you at adjusting valves ?

I have  nice hyd flat tappet in mind that would work great with your setup (2600-2800 stall & 3.55 gears)  This cam is manifold friendly as well. 



Ron

[kycarnut]

I have  nice hyd flat tappet in mind that would work great with your setup (2600-2800 stall & 3.55 gears)  This cam is manifold friendly as well.

Well don't hold out on me. This is the kind of stuff I need to Know before I start and believe me when I say I appreciate all your Help.

How are you at adjusting valves ?

To answer that I have No formal training and just to be Honest I cut my teeth on Chevy small blocks and lets face it it's not that hard to adjust valves on them. So I will have to learn as I go. Thanks Greg

[bigbluedodge]

The 452 heads would be my choice ; hardened exhaust seats and they respond very well to a basic bowl port. Easy 450HP head with 9.5 compression and the right cam/intake/exhaust/carburator. 


Ron

I agree, 452 heads would work better, if your not too concerned about correct numbers. Don't worry about valve adjustment, mopar valve adjustment is easier than chevy's.
Take it easy on that 741 differential.....

[kycarnut]

I agree, 452 heads would work better, if your not too concerned about correct numbers.

Once dressed up with a set of 68 stock valve covers it would be hard to tell the difference? 

Right??   

[kamkuda]

I am a bit of fan of the 915 heds.  The closed chamber allows for strong flame travel and the ability to build quench into an engine.  Plus they are to get a half decent compression with many stock type pistons. (although there are fair more cost effective pistons nowadays)

[b5blue]

Once on and dressed up there is no way to tell I know of.

[firefighter3931]

I have  nice hyd flat tappet in mind that would work great with your setup (2600-2800 stall & 3.55 gears)  This cam is manifold friendly as well.

Well don't hold out on me. This is the kind of stuff I need to Know before I start and believe me when I say I appreciate all your Help.

How are you at adjusting valves ?

To answer that I have No formal training and just to be Honest I cut my teeth on Chevy small blocks and lets face it it's not that hard to adjust valves on them. So I will have to learn as I go. Thanks Greg

Here's a nice grind ; Crower HDP282 on a 112* LSA (manifold friendly) Nice lope, lots of manifold vacuum and works fine with stock rockers/pushrods (NO valve adjustments  )

http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=32243

I agree, 452 heads would work better, if your not too concerned about correct numbers.

Once dressed up with a set of 68 stock valve covers it would be hard to tell the difference? 

Right??   

The casting number is under the valve cover....you cannot tell them apart w/o the valvecover removed.



Ron

[kycarnut]

Thanks RON you're the coolest  .

So just bench racing for now I have:
                                                   68 date coded block bored 30 over

                                                   452 casting heads with 3 angle valve job

                                                    The Crower cam you recommended

                                                    Stock 68 intake and stock Exhaust manifolds

Now what I still need:    Pistons, rods, stock crank?, and maybe Headers if you think they will make a big difference. Thanks for All your Help. Greg           

[firefighter3931]

Greg, i was under the assumption you had a stock shortblock at your disposal ? What parts do you have available and what is the budget ? Are you going for the stock look....i had assumed so because you mentioned stock intake & stock HP manifolds as part of the criteria. 

Headers definately make more power and that would change the build somewhat. To get the most out of everything you need to match all the parts ; no point in headers if you plan to run the factory intake. 



Ron

[kycarnut]

Hey RON your right I do want to make the motor look stock. I will have about $3000 for the build and right now I'm trying to create a list of what it will take to build the engine I want(stock looking with 450hp). Then I will go out and find it all.  Other then a 68 date code intake I bought off eBay for 20 bucks I don't have anything else. That is why your advise is so valuable to me right now. I've never built a Mopar engine before and have NO ideal what will work and not.  . I'm counting on the experience of you guys to make it all come together. Thanks for the  Greg.

[FLG]

Would wait for Ron to chime in...

But im selling the rotating assembly from my 440 short block...all brand new stuff.

The pistons are flat top replacements which in your case would not work, or rather would not be ideal...but the cast crank and LY rods, and new set of lifters just might. If Ron says it will work and you want it ill let it go for cheap. All new never run stuff.

[firefighter3931]

Hey RON your right I do want to make the motor look stock. I will have about $3000 for the build and right now I'm trying to create a list of what it will take to build the engine I want(stock looking with 450hp). Then I will go out and find it all.  Other then a 68 date code intake I bought off eBay for 20 bucks I don't have anything else. That is why your advise is so valuable to me right now. I've never built a Mopar engine before and have NO ideal what will work and not.  . I'm counting on the experience of you guys to make it all come together. Thanks for the  Greg.

Greg, your best bet is to find a 68 440 core motor for the rebuild....it will have the correct looking harmonic balancer and steel crank. The rods can be reworked/reconditioned and all you need is a set of Speedpro 6-pack replacement pistons to complete the rotating assembly. With an open chamber head like the 452 your compression will be in the 9.3:1 range which is compatible with pump fuel. 

Would wait for Ron to chime in...

But im selling the rotating assembly from my 440 short block...all brand new stuff.

The pistons are flat top replacements which in your case would not work, or rather would not be ideal...but the cast crank and LY rods, and new set of lifters just might. If Ron says it will work and you want it ill let it go for cheap. All new never run stuff.

Normally I would say a cast crank is fine for that power level (and it is) but Greg is looking for a stock appearing "correct" 440 for his car. The thick harmonic balancer is a dead giveaway that the engine has a cast crank which would be "incorrect" for a 68 model car.

To me, function outweighs form...but that isn't the case for everyone. Personally, I would have no problem running a well machined/assembled cast crank shortblock in a 500hp street/strip type build. 



Ron

[FLG]

Yep i figured that...already sold the forged one.

Im same as you Ron, dont care what it is...if it looks good and works the same way it looks im all for it.

[71383bee]

Headers ALWAYS make a big difference.  Unless you are running in pure stock or trying to win judged shows I highly recommend them.