ive never done an AWD conversion on any car, but i will tell you even on DSM's like the eclipse/talon with AWD/FWD, there are a lot of differences in chassis alone, and those are the same type of car...not to mention drivetrain differences.
the CRV uses the same brakes as the prelude, so there are probably some similiarities in the rear suspension...wouldnt bet on it tho
if you want AWD, i heard of a guy who put a built h22a into his AWD CRV, i hear its pretty damn quick outta the hole and all around.
the thing about the s2k engine is that the 2.0 makes less TQ than the h22a, and a h22a can make 240HP NA with mods and tuning. probably be less than a f20c swap. and of course it makes more TQ stock.
im sure you can see the importance of TQ in a 3000 pound car. especially when we drive hondas which traditionally make low TQ
now the new s2k has the f22c because honda got smart and added more TQ to help the s2k in its track performance.
~boom