what modifications do i need to have done on an '91 integra. I want to swap my gs engine with a ITR engine. What engines are recommended and what are the legal paper work, and formalities that must be adhered to.

also is it possible to convert my engine b18a1 from my '91 integra to a vtec type engine?

 

You won't need any modifications to do the swap. You can use your stock mounts but it would be easier to use a cable tranny since your car already is one. But Hasport does make a cable to hydro conversion. Since your car is OBD-0, you're going to have to do some wiring/ecu/injector work to convert the OBD to the correct OBD. For the year your car is, the B16a is the easiest swap. If you want to go bigger, the B17a(gsr) from the '92-92 Integra is the next engine though it is an OBD-1 motor but since it has a cable tranny it would be easier than the B18c from '94+ Integras because they are hydro trannies. So that should answer your answer on recommened swaps, and getting vtec. Don't forget LS/VTEC also....