Swapping Cat help plz

Im swapping my stock cat for a Bomz high-flow cat. I was wondering if there will be any problems i will run into. It should be a straight bolt-on affair. Also on one end i think you need a donut gasket, so could i use my stock one? Thanx in advance for input.

It should be a straight bolt on deal no mods required, Yes you can reuse the factory Dohnut seal from the end of the header. Just make sure that they shipped you the right cat. The 90-91 and the 92-93 integras had different lengths. The 92-93 is slightly longer