I second your recommendation! I just installed my Spintech exhaust today, wow what a frieking awesome sound.
Just for reference I'll let everyone know that on my old Pontiac I used to sware by Flowmasters and always had compliments on my 3 chamber Flowmasters, with my Pontiac 400, excellent sound, that's the standard that's been set in my mind for 10+ years.
But today was the first time I've ever heard a Spintech exhaust and it's kind of hard to describe, very unique, just like Borla is unique. It's very deep sounding but not droaning. It's got a very sharp clean sound to it when you rev up the engine. It's not crackly or annoying like glass packs, and not muffled like turbo mufflers. It's just different.
On my setup I ran 2.5" pipes from the engine to the muffler. The muffler has two inlets and one BIG outlet. Right now its still using the Ford factory 2.75" tail pipe and I still have all (4) cat converters. Tomorrow I remove the rear cat converters and if it's not too loud I'll replace the entire tail pipe with a full on 3" pipe on an angle cut instead of side outlet.
My goal has been ultimately to gain MPG, and at the same time make the engine slightly gutsy sounding instead of silent like it was. If at any point it begins to sound annoying or too loud then I'll take a step back and make it quieter again.
The reviews I found on this site showed the CFM of all different muffler brands and Spintech was pretty damn good, almost double the CFM flow of Flowmasters. The better flow is my plan to make every part of the drivetrain as efficient as possible.
