So I watched a video comparing a Magnaflow, a MBRP and a Flowmaster but only the Borla was identified as a S Type. It showed the Magnaflow decimal reading at 116.8 while the Ford 5.0 stock muffler is 120.9 !! So I go to the shop wanting the MBRP but I don't have a part number. It also said the black tips on the Magnaflow are warranted for only one year!

 

I replaced my stock muffler/tailpipe only because the muffler had a rust hole (Damn living in the Rustbelt!). Since my truck was a 7.5L, it already had a 3" single in, but those dual 2-1/4" outs. I replaced the stock muffler with a Magnaflow stainless 7" round straight-through single 3" in'/out and 3" stainless single tail. Still semi-quiet for regular street driving, but sounded MUCH better when I'd get on it a bit!!!!

 

The decimal level on a Magnaflo was 116.8 while the Ford stock muffler is 120.9.

 

WHICH Magnaflow? Length/ diameter/ type?

So what are you trying to achieve??? Loud isn't necessarily better. Quiet isn't necessarily better either. Look at restriction to the exhaust flow.

My 'other' car has a 393W stroker. I used 2-1/2" back to the Dynomax Super Turbo mufflers, and 2-1/4" mandrel-bent tails. I ran back-to-back dragstrip runs with/without exhaust after the headers and got the same ET/MPH, which tells me that there was no adverse restriction. Still a quiet exhaust.

 

Don't blame me for that lack of detail. I thought the same thing. No part number no description. yet they had a decibel meter anf sound at different rpm levels. I was alarmed when I say the decibel levels for the Magnaflo vs. stock. The same holds true when I have asked owners they respond only with the product name which does me no good