gen III heads on a gen I block

do they fit?

Nope, they have only 4 head bolts, they are set up for a reverse direction coolant flow where coolant enters at the top of the engine and leaves out the bottom, and their valve geometry is different. The only thing in common between a Gen III and a Gen I small block is the distance between the cylinders.

Too bad they don't fit, somebody ought to make a set that fits the gen 1 block.
I didn't think the GenIII motors were reverse cooling like the Gen2's, I'll have to check into that again.