I have a obd1 gsr swap in my del sol and need to get new cat to pass emissions. Since i have custom piping anyway does it matter which catalytic converter I get as long as the inlet/outlet size is right with my header and piping?

my high flow failed emissions so i'm looking for oem. anyone know if oem style like ebay one below will function much worse than an actual honda oem?

http://cgi.ebay.com/ebaymotors...14203

 

I'm sure it will work just fine!