Thanks for the information Sawby4president and others.

I would much prefer to have a 366 over a 350 engine, the 350s are everywhere and a dime a dozen compared to the 366, I did not know they made a 427 version of the 366.
I would think the head and manifolds for the bigblock 366 are not the same as for the smallblock V8s aplication, so the question is are the intake manifolds the same for both big and small block GM meaning the 350 carb will fit on the 366 and 427s intake manifolds.?

I would also still like to find out if they made a cheap low nickel version for the 366 blocks in Mexico,? if anyone knows when they started doing that was it 1978 like the 350 engines.?
From my unverifyed understanding so far from talking to many folks is that the 350 engines were substantially cheapened up and made in Mexico starting in 1978, around the time that the Old Flint MI car and truck plants started to close down for good.