lol!
Motor mounts? A few bolts to swap out new ones?
Change ECU? Remove the cover and remove a couple bolts? Unplug ECU, plug new one in...
OBD1 to OBD2 conversion? They make conversion adapters. My OBD2b to OBD2a was home made...
b-series has 2 o2 sensors? Only OBD2 cars have two and since a conversion adapter harness would be used you wouldn't need both anyways.
The real issue is finding axles to work without swapping out all the suspension...and that's not even difficult.
The whole 35 extra lbs is gonna cause you to drive straight off a cliff right. The saving of switching to a carbon fiber hood would compensate for it.
Need proof, see them on a scale...
http://honda-tech.com/showthread.php...ght=h22+weight
The H22 is the best bang for the buck. 30 seconds on a search engine will yield a complete parts list for both the B and H conversions in a Del Sol. People have been doing it for well over a decade now and bolt in kits are readily available everywhere. It's a simple swap. Screw using an automatic transmission though! Manual conversion are easy on that chassis. OP needs to learn to drive a stick.