273 or 225?

Early A’s use the same K member for v8 and slant. He just needs the motor mount brackets. If he goes aftermarket/Schumacher v8 mounts he won’t need the drop center link, as they raise the engine enough to clear the link.

The v8 throttle bracket and the exhaust manifolds are all he really needs from OEM, pick up a 318 magnum from the salvage yard and find a small block 904 and he is on his way.

Or just run the 65 drivetrain as is since he will have it. Adjust the valves, set the points, adjust the timing, make sure the carb is good, and the vacuum advance is working.