302 question for JM

[GaryL]

Year ago you recommended the GM .028" head gaskets to me. There is alway a lot of discussion about quench on hipo engines. With an undecked block and a .028" gasket the quench ends up a little higher than what is generally recommended. How do you build a 302 and what do you consider the proper quench for stock rebuilds? Thanks.

[fireZ]

I use a 0.040 head gasket on my engines that have not been decked. It lowers compression a little but street-able on pump gas.

[Jerry@CHP]

We usually use the 711 or the composition GM gasket that's about .030" compressed.  Depends on where the piston is at TDC.

Jerry

[69Z28]

We usually use the 711 or the composition GM gasket that's about .030" compressed.  Depends on where the piston is at TDC.

Jerry

Hello. I was asking about what gasket to use on the T.C. site. I have a .030 over bore stock rebuilt DZ engine, balanced. The pistons are .021 below the deck and block surface has not been decked. Just a little confused from the answers provide due to the quench specs. What would be recommended in this application?

Thanks, Gary

[GaryL]

It sounds like quench is not that important in a 30-30 cammed 302 for some reason.

[Jerry@CHP]

I would use the 711 gasket.  When you get into this quench topics then it becomes more of a Stock Eliminator get every last HP issue rather than a good running 302 for the street.  Don't worry about what everyone thinks, I've been in this hobby long enough to know that you will get 100 different answers from 100 different people.  We get about 360-380 out of a stock rebuild on a pedigree 302 on pump gas.  We can step it up from that if requested. 

Jerry

[69Z28]

I would use the 711 gasket.  When you get into this quench topics then it becomes more of a Stock Eliminator get every last HP issue rather than a good running 302 for the street.  Don't worry about what everyone thinks, I've been in this hobby long enough to know that you will get 100 different answers from 100 different people.  We get about 360-380 out of a stock rebuild on a pedigree 302 on pump gas.  We can step it up from that if requested. 

Jerry

Thanks for the info. Where can I get this 711 gasket?

[Gramps69Z]

GM part #3830711, check with your dealer. Compressed thickness is .026".

Google the part number and see what happens.

[69Z28]

Thanks

[Jerry@CHP]

John,

They usually compress to .020" when we check them on tear down.  I suspect that they can vari.  This is what I have on my current 302 in the race car.

http://www.youtube.com/watch?v=L-2GZtY9REY

Jerry

[CVKUEBER]

The 3830711 is currently on backorder from GM. I do have a set in stock if you cannot locate them locally.

[Gramps69Z]

Jerry, I was going with what GM stated on their web site. 

http://www.gmpartsdirect.com/performance_parts/store/catalog/Product.jhtmlPRODID=701&CATID=697.html

FYI, the 902 DZ carburetor is working great. It's amazing how you can take a 40 year old part and make it new again.
Thanks again for the professional service.

[Jerry@CHP]

Thanks John!

I hope that these gaskets are not being discontinued.  The back order issue is not a good sign.

Jerry

[Indy 69]

That part # 3830711 does come up as discontinued from what I have found. 

[GaryL]

Jerry, you recommended the #10105117 to me 4 years ago. Have you changed or possibly the "117" was transposed to "711"? Thanks. No matter the composition "117 works great so far.