Well, as you mentioned, the rear suspension needs to be updated. I'd use the rear suspension from the AMT K100 Aerodyne. The front suspension needs to be updated. The NTC350 (or whatever it's supposed to be) is archaic by 1990, so my plan is to put a Detroit Diesel Series60 in mine. The double stich transmission needs to be replaced, and I think the interior could use an update (but I'm not sure on that one). Maybe a more modern steering wheel & dash could update the look.