Hello! I’m in the middle of swapping in a t2 motor finally and I was hoping to keep my rb catback. It seems to me I can’t just throw the revII downpipe and presiliencer on there and call it a day so I was wondering what other options I have, or if it isn’t really an option at all

87 gxl

 

You are correct. The RB Rev II downpipe and pre-silencer will not bolt up to the RB catback. The easiest thing to me, if you want to use your RB mufflers would be to get the Rev II Y-pipe as well and then get some custom piping made to go between the Y-pipe and the mufflers, This keeps it at 3" until after the Y splits it to the mufflers. Then sell your RB catback Y-pipe to recoup some of the cost. Any way you go aboutit will require something custom be built to connect the Rev II to a catback of any kind as downpipe and pre-silencer only bolts up to the Rev II mufflers and Y-pipe.

Edit to add: Since you are doing custom piping anyway you could just get a custom Y-pipe made that starts at 3" and splits to the two 2" pipe to bolt to the catback mufflers. I don't mention modifying the RB catback because it is 2.5" befor the Y and you have to deal with that transition from 2.5" to 3" somewhere. I feel it would be better from a performance standpoint to keep it at 3" until you make the split to the pipes that go to the mufflers.