chriswtx

iTrader: (5)

So is there a difference in 317 castings. I thought they all had d shaped exhaust ports, but I saw some pics of a 317 head that looked like it was an oval exhaust port?? so is there a difference in the 12562317 casting vs the 12572035(LQ9)casting??

GRFMotorsports

iTrader: (15)

Nope, all 317 heads are the same whether LQ9 or LQ4

chriswtx

iTrader: (5)

Weird...I've seen pics of 2 different heads both marked 317. one with oval exhaust ports and one with D shaped exhaust...Hmmm whats up with that...?

GRFMotorsports

iTrader: (15)

Are you sure the port was oval and not the exhaust carbon reside on the head?? While the port is a D shape, the exhaust is not... it will leave a round spot on the head making it look oval in a photo. Post up what you have seen, Id like to see it.

GRFMotorsports

iTrader: (15)

I see you edited your first post... I have had a ton of 6.0L core and have never seen an 035 casting head.. not to say there isnt one, but Ive never seen it... sure thats not the part number instead of the casting number?

Richard@WCCH

iTrader: (3)

The 035 casting is a late model 6.0l head. Identical port cores to the 317. No explaination as to why one exhaust look oval and one was "D" shaped.

Richard

chriswtx

iTrader: (5)

Guy on the board here selling 317 heads and sent me pics. They look oval, and he even said they looked oval to him. Weird...Oh well, guess I will keep looking...No hurry...Thanks for the input..

JMBLOWNWS6

iTrader: (17)

Just buy them. Trust me. Use cooper coat on the GM MLS headgaskets.

orangeapeel

iTrader: (18)

I have some on my Z and they are D shaped. But ported as well. Carbon buildup will make them look different unless you have a can of carb cleaner and a rag handy. Pictures do no justice to some things.

Avengeance

iTrader: (4)

GRFMotorsports... and Richard@WCCH.. sounds like you guys are very knowledgable in this topic. I have a question.

Is the deck height the same on the 6.0L 317s vs stock 5.7L LS1 heads? Have you ever seen any variances?

Thanks.

orangeapeel

iTrader: (18)

Not sure. I have both though. My 241's and 317's are milled .030, so mine are the same!

orangeapeel

iTrader: (18)

I would assume that they would be within a thousandth if not dead on. I think that the 6.0l and the 5.7l motors have identical CR's and run same pistons.

5.3litre

iTrader: (6)

Those are no longer the part numbers. Try to put those in gm parts direct and nothing comes up.

Richard@WCCH

iTrader: (3)

Dimesionally the two heads are the same in overall thickness. The combustion chamber volumes are different. The LS1 chambers are approx. 67cc while the 6.0L chambers are 71cc. Total head thickness on stock heads measures 4.750" +or- .003". We haven't seen the factory heads vary more than the .003" limit. Measurements are taken from the valve cover rail to the deck surface.

Hope this helps.

Richard

Avengeance

iTrader: (4)

Awesome.. thanks Richard, appreciate it.

GRFMotorsports

iTrader: (15)

Agreed... I havent seen much of a difference in the ones I have measured. I wouldnt call myself to knowledgeable.... Im learning like the rest of us, I just happen to get alot of 6.0L core in and try to pick up as much as I can.. now if I could just remember it all. Im just now in the process of putting together, instead of tearing apart, my first Gen III engine. Last time I was messing with building a performance engine they had carbs and distributors.. oh yeah and big blowers and N2O plates.... not all on the same engine mind you...lol