[HWYSTR455]

I think 16" is what I have run in the past, but you MIGHT be able to get 18" in there. I don't think so, but you might.

If you run an H instead of a Y pipe, 18" would be more likely. Y pipe and you will most likely be forced to run a 14", MAYBE a 16".

The constraint is the distance from the crossmember to the differential tunnel and tailpipe. If you hang a tailpipe over the rear and put a muffler on there, you will see what I'm trying to get at. (Even if I'm not explaining it well).

This is taking the use of 2.5" pipes, with 3", because of the bends, it will def only be 14", and it will obviously be closer to the ground, too. And it would most likely have to be a 70-74 car.

Later years, like @ '75-up, also have floor pan differences due to the use of cats.

It's been a while since I've been down this road, but that's how I remember it. Hopefully others will chime in, and with more recent experiences.



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