Cam / Piston recommendation for Stock 383 / 70

[CloedFL]

Hi all 

Currently undergoing a complete analysis of my recently bought charger and took a part the complete drivetrain.

Before making it back to a low CR engine, I am planning to put some money into some pistons and cam and would kindly ask you for a feedback on the current research & findings i ended up. To keep it stock like, the heads should remain the same and will take into consideration getting a 440 engine to burn on a later stage.

The engine still has its orignal 906 heads and block
Carb: Edelbrock 600 CFM
Pump: Mechanical Edelbrock Performer Street Fuel Pump
Exhaust: TTI X-Pipe 2.5"

Planing to go with the original rockers and valve springs so i looked for a cam with a decent lift:
Lunati Voodoo (Advertised Duration 268/276, Lift .494/.513)
KB Stock Hyper Pistons, Flat to increase to CR up to 9.5-9.6:1

The car will be feeded with 95 / 98 octane.

Any advice / recommendation ?

BR
Claudio

[PRH]

You should have the heads cc'd, and make sure you understand what the deck clearance, head cc, and gasket thickness needs to be to achieve the desired cr.

If this isn't done, the problems just cascade downward from there.

Forget what the advertised numbers in the catalogs are..... Take the measurements and do the math.

As an example:
383 +.030, std deck height, uncut heads, KB162 pistons, .027 gasket...... Gets you 8.2cr.

Change to kb400 pistons; 8.85cr

Deck block to zero; 9.3cr

Mill heads to 84cc; 9.6cr

You can't get to 9.5 +/- compression with a 383 using off the shelf parts in the short block without milling the block and/or heads.

Plan ahead.

[BSB67]

It's not clear your intentions with the new pistons.  Where you planning on getting over-sized pistons, boring and honing and balancing, or just slapping some new pistons in the current bores??

[XH29N0G]

When I first modified my 383, the next smaller lunati cam was recommended for my 383 (262/268 .474 .494) (http://www.lunatipower.com/Product.aspx?id=1578&gid=362).  It worked very nicely.  I do not know how that one would work in comparison to the one you suggested in your set up though.  Maybe someone here will have an idea. 

[CloedFL]

Took a little bit longer now for the engine shop to analzye my parts but finally they managed it.

Several questions raised up now, beginning from the valve guides:

They mentioned that they have never seen such tiny valve guides (neither in an muscle car). This raised some questionsmarks in my mind so I am trying to figure out that is installed on my 906 heads. Attached, you can see the valve guides. The guide thickness seems to be quite thin and he was not able (?) to press them out.

Can someone figure out if this is "standard" for the 906 heads or which replacement i have to look for? I am not yet very deep into all the specs of the big blocks






Due to the fact that I am unsure if they will be able to manage to rework the heads for a decent price, I also want to check the possibilites to get new heads.

What would be your suggestion in combination with :

Carb: Edelbrock 600 CFM
Pump: Mechanical Edelbrock Performer Street Fuel Pump
Exhaust: TTI X-Pipe 2.5"
Lunati Voodoo (Advertised Duration 268/276, Lift .494/.513)
KB Stock Hyper Pistons, Dome, .04 oder .06 over, engine must be bored / honed to min .04

BR,
Claudio

[PRH]

I don't know exactly how to say this without sounding too condescending.........

The machine shop is unsure of what they're looking at with your heads?

That would be HUGE red flag for me.

Your heads have been refurbished previously, and those are just .500" replacement guides installed.
That is as bread and butter head reconditioning 101 as there is, and the fact that they couldn't identify that would be a bit troubling if I were considering having them redo my heads.

The one thing I see that I think needs to be checked is, the replacement guides look like they might actually be taller than stock, which reduces how much lift you can run before the retainers are crashing into the seals.

in the exhaust pic, it appears there has been a seat insert installed...... Although it doesn't appear to have been blended.

I'm going to go out on a limb and say those heads weren't refurbished by a shop that specializes in performance head work.

[CloedFL]

I don't know exactly how to say this without sounding too condescending.........

The machine shop is unsure of what they're looking at with your heads?

That would be HUGE red flag for me.

Your heads have been refurbished previously, and those are just .500" replacement guides installed.
That is as bread and butter head reconditioning 101 as there is, and the fact that they couldn't identify that would be a bit troubling if I were considering having them redo my heads.

The one thing I see that I think needs to be checked is, the replacement guides look like they might actually be taller than stock, which reduces how much lift you can run before the retainers are crashing into the seals.

in the exhaust pic, it appears there has been a seat insert installed...... Although it doesn't appear to have been blended.

I'm going to go out on a limb and say those heads weren't refurbished by a shop that specializes in performance head work.

I am not sure if they just let the apprentice have a look on it or if they are not aware of what they got from me .
The guy already mentioned that the exhaust guides are worn out and the play of the exhaust valve is not bearable and should be exchanged.

I am quite unsure if i should let the stock heads revised to keep it in original condition or buy a set of new heads having in mind that the 906 heads with the open chamber are not the best choice.

So what would you suggest ? currently i am putting together a big amount of parts @mancini, classicindustries and summit but i was not able to finde replacement valve guides for iron cast heads on their sites. Which replacement valve guides would be needed to run the 906 with 0.494 inch intake & 0.513 exhaust valve lift? Or better putting the heads in my cupboard and get a new set of edelbrock aluminium heads?

BR,
Claudio

[PRH]

When I go through a set of heads, I really prefer to get all the parts myself.
That way there is no question about the parts being correct.

Things like replacement guides and seats aren't the typical items you'll find offered at retail parts outlets.
Specialized tooling/machines are required for installation of those parts, along with final machining after they're installed, so those type of hard parts are usually sourced from wholesalers who cater to the needs of the machine shops/engine builders.

If new aftermarket heads are in your budget, and you're not opposed to using them....... Then I definitely won't try and talk you out of using them.

At my shop, reconditioning a set of old oem heads can easily get into the $800-1000 range, depending on how bad they are to start with.
Even if they were in fairly decent shape, it's usually at least $4-500 just to do the basics(valve job and resurface).

[CloedFL]

When I go through I set of heads, I really prefer to get all the parts myself.
That way there is no question about the parts being correct.

Things like replacement guides and seats aren't the typical items you'll find offered at retail parts outlets.
Specialized tooling/machines are required for installation of those parts, along with final machining after they're installed, so those type of hard parts are usually sourced from wholesalers who cater to the needs of the machine shops/engine builders.

If new aftermarket heads are in your budget, and you're not opposed to using them....... Then I definitely won't try and talk you out of using them.

At my shop, reconditioning a set of old oem heads can easily get into the $800-1000 range, depending on how bad they are to start with.
Even if they were in fairly decent shape, it's usually at least $4-500 just to do the basics(valve job and resurface).

With your answer and the incredible high hourly rate for such kind of works in my country, i think it will be anyway cheaper having a set of new heads. But will talk again to the shop beginning of next week.

Do you have any recommendations with regard to the aftermarket heads ?

[PRH]

You'd have to do the math and make sure this wouldn't cause you a problem with the CR,
But the "if it were me" answer is, I'd use the Edelbrock E-Street 75cc heads.

The one other thing I would caution is, those heads(well, all the aftermarket heads other than Stealths) have angled spark plugs, which don't play nice with every brand of headers.
On some, only minor dinging is required, others can require more substantial "massaging"...... And with others the angled plugs actually work better(like TTi's).

[71 Bee Man]

You'd have to do the math and make sure this wouldn't cause you a problem with the CR,
But the "if it were me" answer is, I'd use the Edelbrock E-Street 75cc heads.

The one other thing I would caution is, those heads(well, all the aftermarket heads other than Stealths) have angled spark plugs, which don't play nice with every brand of headers.
On some, only minor dinging is required, others can require more substantial "massaging"...... And with others the angled plugs actually work better(like TTi's).

Really interested in reading this.
I finally started doing what's needed to pull out my 383 this evening. Once out, I'm checking my heads, and......if necessary......I think I'll be going the Sidewinder route from Moparts. But.....while I've read about the angled plugs, I never thought to check how they'd go on my motor which has Dougs Headers.
Like CloedFL, I really need to work out whether it's feasible to recondition mine or buy new, although my mechanic (who gives me heaps of advice), said that for the cost, I would be insane not to get new ones.