Just tore the heads off of my 440 to take a gander at the remainder of the troubles. Engine would 180* then stop, turn back 180* then stop. Found out there was some rust at the top of cylinder 7.

Question being: Without an A on the secondary stamp of the block (indicating a .020 overbore from the factory), is it safe to say someone has been in this engine if all of the pistons are stamped with the ".030" on the tops of them? I'm new to all of this, but would there be a part number stamped somewhere on this piston that would indicate what my compression ratio would be?

Thanks

Someones been there... You want to know the C/R.. Are they flat tops? Valve Reliefs? Measure how far they are in the hole At TDC... You can get surprisingly accurate results using a feeler gauge & a straight edge... Post that info & you'll get a far better idea of you C/R then any Pt# would get you... Also what cylinders heads.. If you can get an accurate CC of the combustion chambers then you can really see what kind of C/R you'll have...

get a piston in a non rusty cyl as high as it will go & what 1 wild rt said to get your deck height, the last 3 #'s of the heads' casting # & someone will have the nominal CC's and describe the head gasket (& a part #) to get it's thickness and measure it's bore dia and plug it all into http://kb-silvolite.com/calc.php?

Hey Pat, sounds about right for a mid-late seventies motor.

That's what God gave us nitrous for

Yeah, the CR on those engines is pretty pathetic, but at least, it can only get better from there, right?

But, if ya' got rust in the cylinder, I'd suspect you may have a good candidate to go .040 over.

Then you can get pistons that come up to the deck, where they belong.

-Bill