400M... I'm building one for a street / mud bronco guy. Not anything real cool. Basic stuff, nice camshaft, etc. Well, only huge dish pistons are available. They had 8:1 compression in the day.
So, I get the kit, measure dish, head, figure cr... well, 9:1 with piston .010 in the hole.... only problem is ...THE PISTON IS LIKE .08 IN THE HOLE.
So, I rechecked all the math...yup.. that must be how they came up with 8:1.
The potentiol was there. 4" stroke. Decent heads for a peeler (no, not great, but ok...fair).
AND THE DOUCHE BAGS PUT THE PISTON .100 DOWN.
I know, cleveland piston and head, bush rod, yada yada yada.