honestly, you’re way better off going with a 302 than a 3.8sc if you even plan on modifying it any further.
The aftermarket for the supercoupes is next to non-existent and what is out there is some serious $$$ for minimal gains. Back when I was into tbirds there was a member that sank an ungodly amount of money into his car only to run mid-high 11’s.
If you want to just do it to be different, than go for it. Nothing beats the sound of a blower winding up. The transmissions are totally different too. The 5 speed from the sc’s are a m5r2 mazda trans and wont fit AFAIK, but the auto “should” work.
Like I said, a 302 swap seems a lot less complicated it’s cheaper and easier to mod/find parts for.
g/l either way