I found a 91 integra LS with rsx tailights and i'm thinking of buying it but if i bought a body kit would i have to get a rsx rear bumper or could get a regular teg one w/out doing any work on it?

imo, i think that you would have to get a intergra rear bumper. The person who did the conversion most likely just did the lights, not the whole rear end. The mounting points on an 91 integra are most likely in different spots since they have different trunks, side panels, etc.. all that you have to take into consideration. Look at RSX's vs. Integras: is the rear end wider, etc.

I am no pro at body kits but with my exerience with them, at least fiberglass ones is : even if you get a body kit made for the exact year, make, and model of your car with no other exterior mods chances are your going to be doing some extra work like cutting shaving drilling, etc. If you buy very expensive kits, the work is going to be less, but there is always extra work that goes to fitment.

I would get a integra bumper and be ready to do some cutting fiberglassing, etc. The RSX bumper is going to fit even worse, but i guess anything is possible with enough fabrication.

Well i decided not to get the car. The guy was gonna pretty muhc screw me over, he hasn't been inspected for 2 years, needs a windshield, and the system was coming out if he sold it, and the tires were bald. I found a better integra jsut with a damaged rear quater panel and fron bumper which dosen;t mean muhc to me since it's coming with a bucnh of after market parts

well, I'm going to comment anyways. You didnt specify to whether it was an RSX tail light conversion, or an RSX rear end conversion. Most likely, it was just the tail light conversion, so that would mean any rear lip from a Teg should fit just fine, and any bumper should fit too (might need a little modding to fit with tail lights).