I have an 87 442 with a ls engine. My exhaust setup in 87 GN ( 3 in. SS off each bank going into a 4 in. ss with an oval flange to mate up to the 3 in. polished exhaust from, I believe GN Performance. Anyway they are in Ca. The 2 mufflers are 3 in. center in-- 3 in. center out. I need to buy 2...