I'm unable to post to Repair & Restoration, Technical & Reference, General Questions Section so I am responding with a new thread.

2 1/2 exhaust will be perfectly fine on a 1972 Cutlass S. There will not be any ground clearance issues unless you go with an H pipe or X pipe which will cross under the driveshaft. Even with long tube headers running the pipe straight back to the mufflers you will have adequate clearance. I highly recommend the Thrush welded steel case mufflers if you want to keep the price down.

Here is a video of my friend's 1970 F-85 W-31. This is a W-31 350 with factory manifolds and crossover block off, 2 1/2" pipes straight back to Thrush welded steel case mufflers, with 2 1/2" tailpipes. These Thrush welded steel mufflers are made by Walker. Part number WLK-17659 and can be bought from Summit for $29.95.

 

Nah, I bet you can post anywhere. Give it a try. If you really can't then something is wrong and you should send a PM to Omicron. He should be able to fix the problem. Going to try and merge this with the thread you wanted to reply to.

Hmm, could not find the particular thread. Copy and paste it and PM it to me or reply here. We will get this fixed for you.