Avengeance

iTrader: (4)

Im curious... Ive done tons of searches... about deck thickness and I dont know if Im typing something wrong but Im wondering if anyone can answer these Qs.

How much thicker are aftermarket heads vs 317s? How many people have lifted or pushed water with the 317s and big boost? If using some ARP studs with 317s should I be worried about issues with say 15+psi? Im not sure but has anyone seen 317s catastrophically failed due to having a thinner than aftermarket deck?

Ive read some threads here and seems that there are a good handfull of people that have pushed the 317s to big hp.. 800-900+ without issues. My goals are somewhere in that area.

My reason for this thread is Im having a iron 370 built soon and my target is about 8.9CR.. with the pistons I have picked out and the proper gasket diameter I can get this with my 72cc 317s. With the money saved by sticking to the 317s I could actually have them worked up nicely, PnPed with good valves, for about half the price of a aftermarket head... maybe somewhere like WCCH or similar.

Anyways... I know the general consensus will be to go aftermarket. Can somone give any good reasons why to not stick with the 317s? Is the answer as simple as flow #s?

Thanks in advance....

dudeman

iTrader: (43)

i think its 3/8 vs. 3/4. i ran 17psi with 317s and ls3 head gaskets with $60 ebay heads studs without issues.

Avengeance

iTrader: (4)

Thanks... if that is correct thats a pretty considerable difference.

dudeman

iTrader: (43)

dont quote me on the thickness, since i dont own a set of aftermarket heads but i read that in hear somewhere.

jay_rich

iTrader: (8)

My LT1 afr's were 3/4decks i'd assume that LS series heads are the same (aftermarket)


Jay

Fireball

iTrader: (21)

I believe the ETPs are ~.800 as cast IIRC

Shawn @ VA Speed

iTrader: (3)

there moe to it than just material thickness in the deck-there is alos the quality of the material-the material in the aftermarket castings in much much better than mass produced oem casting.

i have seen the 317's hold 1000+ rwhp on several occasions-if the everything is right they will hold with no issues

Avengeance

iTrader: (4)

Thanks for all the responses.... much appreciated. I may try to stick with my 317s, if the budget allows it Ill go for some aftermarkets. Maybe Ill start searching for a nice used set of 72cc aftermarkets.

digitalsolo

iTrader: (24)

Shawn,

What do you figure the difference in max capability is (without pushing water on a regular basis), between the OEM and thick deck heads (in 4 bolt)?