RV specific heads are different,and not worth saving for any muscle car application.
They have extra water jackets where the Water pump housing matches up with the heads and also not worth saving.
They also have angled spark plug holes,FYI and different exhaust manifolds,too.
Mid-late 70's blocks have a higher nickle content and thicker cylinder walls which is good.
Made for torque,compression is anemic and the pistons do sit way down in the hole.
Cranks will do fine but just need the typical balancing to match new pistons,etc.
Hope this helps