are these "GM CRATE MOTORS"? I do not know enough to be able to tell..... someone raised a question and now I wonder.....

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Looks like a gm crate motor to me. Whats the compression ratio,the domes look bigger than my stock 502 had,Smitty

Here is picture of mine if it helps

Looks like my crate motor

thanks guys, I am having to go piece by piece, part by part, item by item to find the problem.....

having guys to bounce stuff around with helps alot.....

Don't forget that gm crate motors typically have 11 lb differential oil bypass valves instead of the 30 lb ones merc uses.Stock merc oil lines and coolers are restrictive enough to allow bypass valves to open during normal operation,especially if your motors have high volume pumps. This will cause your oil temp to go sky high when oil bypasses the cooler plus it will not get filtered either,Smitty