I'm building a 383 sbc with aluminum patriot heads. Pistons are .015 in the hole. I really want to keep the quench as clos to .040 as I can. I had the victor 5746 but then realized that with the 4.100 bore that the gasket stuck in the cumbustion chamber on the exhaust side a little. Can I use the embossed shim gaskets with aluminum head? Jegs makes 1 that would be perfect @.024 thick and 4.150 bore. Just need to know if they will hold up. Thanks for the help.

I wouldn't think those gaskets would pose any particular problem with the aluminum heads. As long as the block deck surface and the surface of your heads are nice and flat/clean, they should seal up decently. I've heard of other guys on here using the Fel-Pro 1094 embossed shim gaskets with aluminum heads without issue. Of course you wouldn't want to use that particular gasket since it's only .015 thick, which would put you at .030 quench height, which is too tight.

Thanks for the reply Pat. The heads should be flat because they are being machined .012". The block should be as well. If I wanted to check, whats the proper way and or tools to use? What tolerance would be considered flat? Thanks again.

From what I was taught, the way to check your block deck surface for flatness is to lay a machinist's straightedge across the deck and then see how thick of a feeler gauge you can slide underneath it at several different points. Lay it straight across horizontally, then diagonally each way and check your clearance. If it's about .003" or less you should be fine. If your clearance is more than that, you'd probably still be ok with a composition style head gasket, but of course it needs to be pretty flat for a shim style gasket.

ok thanks again

Another alternative that is real close is the GMPP .028" composite head gasket. I use them on my mild 383 blower motor with aluminum AFR heads. Only about $30 a pair from Scoggin Dickey.

Yeah, I was gonna mention that gasket too, but a lot of people are afraid to use it due to the gasket bore size being listed as 4.00. However, Dyno Don posted a while back that he uses them all the time on motors up to a 4.060 bore size without any problems. Being that it's a composition type gasket, it'd seal up really well too. That'd put the quench at .043, which isn't bad at all. GMPP also lists that gasket as being good to use with aluminum heads.

The gasket bore of those GM .028s is 4.100". or there are these:
http://www.competitionproducts.com/p...number=HG31600

Thanks guys for the replys? I will check into those gaskets? I found those HG31600 Gaskets in town. Does anyone have any info or has any used these gaskets before?
http://www.competitionproducts.com/p...number=HG31600. Thanks again guys.

make sure whatever you do, dont buy a cheap one! i bought a fel-pro .017 thick head gasket and i blew that thing in less than a year! it was only like $20. DO NOT GO CHEAP ON HEAD GASKETS it cost me $500 lol dont make the mistake i did

Thanks for the reply.I think I'm going to go with the felpro 7733pt2.

You realize you're going to lose all benefits of a good quench with those right? Those gaskets are a great, economy gasket for rebuilding a totally stock motor, but I'd seriously suggest something a little better for a motor with a nice set of aluminum heads. I scrimp where I can on costs, but that's probably not a good area to go with the cheapie stuff. Just my

Thanks again for the reply. I have to have at least a 4.125 gasket. I cant find any thing except a steel shim gasket. My builder didnt like the idea of steel shim gaskets with alminum heads. If you have any ideas, I would appreciate it?

If the gasket bore size is your primary concern, and not necessarily the thickness, I'd definitely recommend this gasket over the generic rebuild one. Its 4.166 bore size and recommended for use with aluminum heads. It uses a flattened copper wire around the cylinders instead of flattened steel wire, which minimizes brinelling to the surface of aluminum heads. Here's a link: http://www.summitracing.com/parts/FPP-1010/ Or for a bit cheaper there's these: http://www.summitracing.com/parts/MRG-5800/

Thanks again for the reply. I am worried about the bore size. I have been told by several different shops that all of the gaskets needs to be sandwitched. I dont want to lose the quench and compression but I think I am going to have too.
http://www.summitracing.com/parts/FPP-1010/ I can drive about 2.5 hours each way to get this gasket. Thanks for the help.

just call cometic and have them make you a custom set. if the wallet allows it.

Thanks for the reply. I did, their tech guy didn't recomend their gaskets for alumium heads on a street motor.

Drive 2.5 hours each way? Damn, just order them online. They only charge like an $11 flat rate to ship. They claim it's "free shipping", but there's an $11 "handling" charge, which is , but it's still pretty cheap. And they're lightning quick on their shipping. If I order something from them on say, Tues. or Wed., I'll usually have it on my doorstep by that Sat. Btw, all the shops that are telling you that you need a "sandwiched" gasket are probably referring to the MLS (Multi-Layered Stainless) type gaskets. Granted, those are about the best gasket you can use with aluminum heads, but they're pretty spendy. Those FP 1010's will do the job just fine, and cost quite a bit less.

Thanks for the reply Pat. It was about a 6 hour round trip, but i got them. Fel Pro 1010, Ihave them installed already. You missed understood me about the gaskets. What I meant was that the gasket had to be pinched between the two metals. None of the gasket could protrude on the bore or the combustion chamber. That fel Pro Gasket was not cheap. It looks like a good gasket, its composit with sealer at the critical points. Thanks again for the reply.

I had those HG31600s in when I had my '88 IROC 355 running low 10s in the 1/4 mile. Low cost doesn't mean low quality.

Atilla, thanks for the reply. Was that an all out race car? Was It street driven. What type of heads did you have? Did you have to occasionally reseal those gaskets? I was told not to shim or metal gaskets with a street motor. Thanks again.

Ok, I see what you meant. In other words you wanted to make sure that the fire ring portion of the head gasket that goes around each cylinder bore would be able to line up with the edge of the combustion chambers on the heads right? Yeah, the 1010's cost a bit of money, but I'm glad you went with those instead of the "rebuilder special" PT-7723's, and the 1010's are still a lot cheaper than the MLS type gaskets. Glad to hear you got it all worked out!

Pat thanks for the reply. Yes, with the 4.100 bore gasket, the fire ring protruded on the combustion chamber just enough to make it scary. It sucks to have to give up that quench, but I know its the right choice. Thanks again for all the help.

That was my daily driver, I was using AFR 180 heads and a pair of junkyard turbos. I personally shaved .009" from both decks of the ZZ4 block, and I also surfaced the heads by .004" when I took them out of the boxes. I used ARP studs. I had that engine for 3 years before selling it. I never had to remove the valve covers after initial assembly.