some guy already did a SHO swap in a fiero a few years back… he said he’d never do it again cause it was such a PITA. some bob guy. i forget his name.
i think a turbododge setup in the back would be pretty easy and not much heavier than the stock 4 banger weight though id rather have an aluminum engine in the back to save weight. the turbododge and fiero trannies are pretty similar in many ways. if you use dodge saginaw design inner CV joints and fiero half shafts its possible the dodge tranny wouldnt need any axle fab to fit in there. just make some mounts and adapt the shifter cables. shouldnt be too bad. then you can use the older 555/568 trans (very strong) and a 2.4L SRT setup (the old dodge trans and SRT/2.4L/2.0L DOCH motors mate up other than one bolt and you can easily make a tab to join the different holes up) and have factory turbo power in there. the only GM factory turbo setups are the lousy LT3 2.0L sohc and the newer ecotec turbo… while the newer ecotec turbo motor is really nice, the ecu is going to be a pain. the older dodge turbo ecus are fully cracked and cake to wire up as a standalone and the computer can be in the engine bay or in the little trunk back there no problem.
Brian