1990 GT-Four considering engine swap?

[Im.Jiggly]

Hey there, never posted on this forum before, mostly talked about 3s things with other owners I know in person. I own a '90 GT-Four with about 160k on the clock, been saving for a while and I've been considering building/swapping a new motor. already have had major suspension work done and minor motor work as well, mostly the head and turbo, and on the tune she's about 210ish KW at the wheels. I'm debating whether or not to swap a 6th gen 3S-GTE in from a 205 if I can find a decent condition one, but I was wondering how difficult it would be to convert the famed '97-05 black top Beams 3S-GE from the Altezza RS200 to a GTE (obviously with minor work and a tune)? Quite specific I know, but was curious if anyone has had any experience with this sort of thing before? Alternatively, I've seen quite a few people suggest I go with a sort of Frankenstein mix of a 3S and 5S to make a 2.1L, I believe that's with the head of a 3S and the block of a 5S? Any input/opinions would be appreciated 

-Justin

Edited October 16, 2019 by Im.Jiggly

[Hiro]

16 hours ago, Im.Jiggly said:

but I was wondering how difficult it would be to convert the famed '97-05 red top Beams 3S-GE from the Altezza RS200 

FYI the Altezza RS200 3SGE is the blacktop BEAMS not the redtop (and is designed for RWD layout).  The redtop BEAMS (which only has single-VVTi rather than the blacktop's dual-VVTi) is the correct transverse layout and came mainly in the ST202 Celica and SW20 MR2 (but not all models)