A parts dealer told me about a black 0.028" black head gasket that is supposed to be really good, he said they seal really good. Has anyone heard of these and if so what is the GM part number?

Im thinking it's probably this one:

http://www.summitracing.com/parts/nal-10105117

Note the bore.

This one

14096405

Yeah, they work really good. Used them many times. Even have them on my mild 383 blower motor.

I have used this one myself with good luck. AFR heads and ARP head bolts.

Found'em on summit thanks!

FYI- GM makes a different one if your block has been overbored. It's a different construction (silver appearance) but is designed for a block that's been punched 30-40 over or whatever. Still .028" compressed thickness.

When they say that black gasket is ONLY for a 4.00" bore, they're not kidding. It comes RIGHT UP to the edge of the bore. Even at only 30-over there would be overhang.

I would use it on an overbored 305, too, no questions asked. It would be perfect. And, of course, you can't argue with the price.

No this is a stock engine, it should still work properly correct?

Yes.

Hmm, I am running the Victor-Reinz 5898 gaskets. They are .026" compressed, but on a 4.1" bore.

Kind wish I had found these these before for my LT1.