Pics of crossmember here, post 103. 435 on top, 4500 on bottom
http://ramchargercentral.com/mopar-trucks/1988-w-100/100/

if anything you may have to drill 1-2 more holes in your frame and use existing crossmember, though it will be further back. But maybe not since you started with a 445 instead of a 435

use the 143 tooth 11 inch flywheel for your engine, or have yours ground if its already same dimensions, but measure it fist0 runout, thickness, etc. Just use the flywheel for your year engine

4500 bells are hydraulic- mopar perf used to recommend the 95 dakota set up so it sounds like you're on the right track there

clutches were messed up in 92-93- started with 19 spline input, then went to the 10 spline for the rest of the production run. One of the clutches was scalloped as well and dont want to mix and match scalloped flywheel with flat clutch, vice versa.

I assume you already have a divorced transfer case?