I used a Summit 2 1/2" system on my 68. Guess what - my passenger side didn't exit straight either. What I did was pull it back off the car, put a piece of 2 1/4"ish tube inside it and bend it a bit. Eventually I got it where I wanted it. there's a little less clearance over the axle on one side than the other, but it doesn't hit or anything. Also it was a royal pain to get the exhaust to not hit the body and vibrate anywhere. If I had it to do over I'd definitely inquire at a shop about prices for a custom system.