My Borla dumped is quiet!!
I had a very similar 5" case Dia., 3" inlet/outlet Magnaflow , #12867 in the I-pipe that I had dumped, It was also quieter then i thought it would be.
Trending Topics
Dynomax doesn't offer a 5" dia., and that's the largest size you want for the I-pipe. Otherwise you lose ground clearance and probably have clearance issues with the drive shaft, and that's with just a 3" drive shaft, not a 3.5 or 4" shaft.
Now their Ultra Flo (oval ) mufflers are a very good option for the stock location to tone down the exhaust.
The Best V8 Stories One Small Block at Time



