Not Ranked
I have 3" OD exhaust pipes on the 289 FIA race car. I use a straight through muffler, I believe that it is a dynamax, that is about 3.5" OD. They do scrape a little when I am going over the curbing and they would hangup a little trying to be the car on a beaver tail open trailer. I have the transverse leaf springs and have installed a 1" lowering block on the front and 1.5" lowering block on the rear. Before I added the lowering blocks, unless I went over high curbing, there were no issues with contacting the race track surface.
Normally, people do not use mufflers on race cars, but I kind of like my hearing. Even with them, it is loud with the pipes exiting just in front of the rear wheels.
Jim
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