325i vs 325is

the only things that are dif are adjustments of suspension and sporty interior/exterior right???

so wouldnt that mean that all the 325i's performance (engine) parts fit the 325is???

if so that would be great because it's alot easier to find a manual coupe is than a manual coupe i

and performance mods im tlaking like, turbo kit, intake, chip, injectors, etc

If you're talking an E36, I don't think a 325i coupe exists.

so the engines are the same right?? so chips and stuff should work

Yep.