Lol, I've done it. I started with an 89' in 03'. KA24E, I put ITB's on it. I'd spin the rollers at like 124 whp on a mustang dyno. Then I went to a KA24DE, I ended up putting a turbo kit I pieced together with pieces of Mitsubishi's, Subaru's, all kinds of crap. I got it up to I think 170 whp before I grenaded the block due to catastrophic overboost. I did my first SR Swap in my second S13 in 04'. Took me FOREVER to get that bastard to turn over. I thought for like three weeks I'd spliced the harness wrong. Turns out my starter was dead...
After that, game on. I loved that second S13. Then I imported one legally. It was an 89' Sil-80 with the CA18DET in it... and it was black... that was my baby.
I've run KA, CA, SR, RB20/25, and a VQ35DE car. Love all of them. Some ppl like classic mustangs... I love S13's