Intake. With a low cowl car intake height might be an issue. Any problems with the current set-up? Use that as a gauge for install height.
Carb. On my 427W I've run a 670 & 770 Street Avenger vac secondaries & choke, then a ProSystems 780 & 940 double pumper, no choke. Started with a Performer RPM and switched to a Vic Jr. For most I'd offer the dual plane manifold and the 750/780 double pumper. Never figured I needed the choke. The 940 was way too big until 6,000, ran great at 7-7,500.
Ignition. Ran a MSD billet distributer and a Crane Hi-6 ignition and coil. Worked well for me, Hi-6 was flawless.
The steel flywheel provides a bit more rotational mass, might be easier to drive but I doubt that it's a big deal.
Clutch. The last "normal" one I used was a Centerforce dual friction (??). Nice piece.
I'd take the opportunity to check and clean everything, Flush the
oil lines if you are using/reusing.
Oil coolers are a PITA to clean. Flush the radiator and lines.
I had motors in & out of my SPF cars regularly. I'm hard on toys.
Jim