I have an 82 280zx that I'm building a new exhaust for. I built the downpipe out of 2.5" mandrel bends, and want to now replace the cat and go the rest of the way also in 2.5" pipes. I can't decide on the muffler - any recommendations? Looking at Magnaflow 10416 (round) or 11226 (oval). I think for a cat, Magnaflow 53956 ought to work, right? We don't have emissions tests where I live, just a visual.

What do you guys think of these choices?

Right now, the car has a 2.5" downpipe from the turbo to the stock cat, and 2" all the way back to a straight pipe. Its not too loud but I do need to be quieter for some upcoming track events. Thank you!

 

Update: probably going with Magnaflow 12616. Its 6 inches round, versus the 10416 that was only 4 inches.