I had a flowmaster put on recently; they removed the stock muffler and put a dual inlet, single outlet flowmaster on it.
Now that I have been doing my homework here in this forum, I want to take it back in and have them remove this single exhaust and go dual exhaust with two 40 series from the cats straight out the back of my truck, my question is should I have them install 3" pipes from the mufflers back, or stick with 2.5" pipes like the stock pipe already on the truck? And what difference would their be either way, sound quality? Gas mileage? More power?

My truck is a 2000 F150 XLT SCab with the Triton 5.4l thanks.

 

Dual 2.5" or single 3" works best for the 5.4L that is near stock in power. Dual 3" would be too big and most likely loose low engine speed torque.

 

Thanks for the info, I'll have them do duel 40 series flowmasters with 2.5" pipes from the cats back. He quoted me 420.00 installed. average price?

 

If that is for true dual and including tips, I'd say that is pretty good.

Two Flowmaster mufflers: $120
Two Magnaflow tail pipes pre-bent: $80
Two polished stainless tips: $50
Extra pipe, hangers, labor $100-150.

 

Ron's Muffler quoted me 325.00 for everything, installed. Sounds like a good deal, have to wait till payday though :-(