I was planning to change heads (LO3 TO L69) and could not find a 305 head gasket Weds. that was any thinner than .048.

I have on hand a .028 GM 350 head gasket and was wondering if it would hurt to use it.

It seems that even though the chamber rings are larger for the 350 the thinner gasket would keep the compression more in line with stock.

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91 RS 5.0 TBI....LT4 cam....Edelbrock headers....3"Dynomax exhaust....5spd.... 3.08.....Ultimate tbi....afpr...ZR 255-50's...Koni's

 

The only problem would be on the head side, you want to make sure that none of the coolant passages will be exposed to the combustion chamber with the gasket in place. The problem area is usually where the spark plug is, theres a passage there that I have seen on some that the fire ring on the gasket wouldnt cover the whole passage at all. You would probably want the fire ring plus a little gasket material between the coolant passage and the combustion chamber to be safe. Make sure the gasket is lined up in the correct spot when you check it.

 

Thanks, I will check it out. I have never tried to use different displacement gaskets before.

 

FYI
Nope, the fire ring is right on the edge of the coolant passage. Guess I'll order the one's for the 305 to be safe.

By the way why aren't thin replacement gaskets the norm in the rebuild kits?

The one that came off was .022 or less.

Thanks!

 

Dont know, Fel-Pro and Pioneer both use ~.040 gaskets and have been doing that for a long time. I dont really care for the thin gaskets, but thats what GM used. I guess FelPro and others feel the same way.