Review on 🚗 MagnaFlow 7in Round Center/Center Performance Muffler 12774 - Straight-Through, 5in Inlet/Outlet Diameter, 24in Body Length, 30in Overall Length, Satin Finish - Classic Deep Exhaust Sound: Find the Perfect Muffler for Enhanced Performance! by Ron Turner

Well I was quite surprised to see that the 5" Magnaflow resonator was narrowed to 4" across the entire resonator. Contacted Magnaflow and never received any information. Mounted on ISM Cummins 450 hp. Timed out waiting for a reply and installed anyway. This probably won't be a problem, but it seems to me that this should be disclosed as the 4 inch limit. That sounds good. Definitely a five star component and very nicely built. There were a few shipping dents on the outside and one end was bent from a fall. Not their fault, but remarkable. The end of the box has been torn off, this is a silencer, not for the buyer, so everything will be fine.