I've got a late 1998 B5234T3 (High Pressure Turbo) in my C70. It's getting close to 240k and has already suffered a head gasket failure. It really hasn't quite been the same since.

I've located a replacement engine locally which appears to be from a 1999+ model and features the variable valve timing, direct ignition system, and electronic throttle. It's an engine/tranny combo and could be a real deal, but the original car is long-gone, so no chance for additional parts

What are the potential problems if I swap this new engine into my car? will my engine computer work, or will I need to source a replacement? Can I use my original throttle setup, or will I need to find a complete electronic setup? Will my on-pump power steering, and MAF sensor up work on this engine?