Just as slow as before mods..

With engine off have someone get in car hold gas pedal to the floor. Not take air cleaner off and look down in carb and make sure throttle blade is wide open. Easy peasy.

Compression test, verify firing order all plug wire correct, check spark plug gap, put some Timing Tape on balancer and verify initial and total timing.

Dana rear? No worries about breaking that with a 318....