I installed Spohn Subframe connectors on my car in 2014 when it still had the original 305 exhaust setup. When I swapped in the 350 in 2016 I stepped up to DynoDon headers with his Y-Pipe and a 3 inch catback exhaust. Since the swap increased the pipe diameter, the top of my catalytic converter rubs the cross brace to the frame on the subframe connector. This causes vibration in the cab at certain RPMS (especially around 1800) when it rubs on that cross brace and is rather annoying. I'd rather not have to get the brace relocated if I can avoid it, so I'm wondering if there is some sort of heat resistant product that I could wrap around the brace to dampen the vibrations. Or any other ideas that you all would have.

 

Never seen, heard of, or even imagined, any material that could accomplish that. Not a viable "plan".

Adjust the exhaust position.

Find a smaller diameter cat.

 

Adjust the pipe with a hammer. Won't hurt a thing.

 

This outa do it

https://www.harborfreight.com/4-lb-h...mer-69240.html

 

Sometimes the common sense answers like ones given in this thread bring a tear to my eye.

 

I always like to explore all of my options before going with a permanent solution. I'll go out today and see what I can do after work.

 

The stock dual cat setup in my Formula rubbed my Alstons initially. After shifting things around a bit I was able to make enough clearance that the clunking went away. There's a ton of adjustment in the transmission crossmember and the exhaust. Should be able to shift the exhaust down, or the transmission over a hair to give a bit of clearance. Otherwise, pop a relief dent in the exhaust pipe like the big flat spot above the panhard bar in back.

 

Just to follow up: I went out last week and after some effort was able to reposition the exhaust. Its 95% better now with only a tiny rattle at times. I'll take it!