Re: motor mounts
Al had the same initial thought as I did. Correct big block frame stands move the engine to the pass side about an inch, and if you have power steering, you'll need every bit of that inch. I have the correct frame stands and correct exhaust manifolds on mine (driver side manifold has a curve cast into it to clear the PS box), and it's pretty tight. If you're running a manual steering box, you might be okay on small block mounts.
If you did the aluminum parts on a big block and had a car with fresh, stiff small block springs, you might (repeat, might) be okay without changing them. If the small block springs are original, tired, weak rate small block springs, I'd change them.
69 'vert project big block/TKO 600 RR
68 'vert driver RS clone -- gone!