whats the big diff from obd1 and obd0?

can i swap out the obdo and go with the obd1..i like the body style of teg the 91 is..i'm not a fan of the next body style..i could get one if i wanted but would rather have the 91..

i know the ls/vtec setup is pretty good but is like a grand or so..might just do a home turbo kit or something.

whats the hp limites on the internals?? i'm talking on a safe ton also not hand granade tune.