90/91 had inset on bottom of front bumper, 92/93 was pretty much straight, and 94/up ACURA integras have 2 circular headlights...

as far as model differences between rs,ls, and gs, there are many... from power locks/windows... to moonroofs (ummm... can that be plural? or is it moonrooves?? lol) ... mainly just the obvious trim line stuff.

as for engines... and mostly everything else - I'm still a noob so please correct me if i'm wrong. I love the constructive criticism.... :hsdunno: