The 3 inch looks awesome, especially if it's the catback with rolled tips. 3.5 is just too big, bordering on fart cannon big to me. The sound should be pretty much the same since it's a short section of pipe.
__________________
Sometimes I think that government fits that old-fashioned definition of a baby: An alimentary canal with an appetite at one end and no sense of responsibility at the other.
- Ronald Reagan
i think he means the tip. noone sells a full 3.5" exhaust system.. it would be downright rediculous for a 281ci motor producing only about 210whp. Youd be down to about ricer standards if you did 3.5 swap .. Think a bit dude............Ok anyways. Mac makes awesome catbacks. If your talking about a 3" "CATBACK" and not 3" tips.. then it would increase performance atad. if your talking about tips. then i THINK 3" and 3.5" just have visual differences. somone else would probably have more input.. id definatly go 3.5" though
__________________
2001 Mustang Convertible (Cruise Car)...
2000 Mustang Coupe (Race Car)...
Well It's Enough To Kill ANY Of Those Jap Cars
"Real Cars Don't Power The Front Wheels, They Lift Them"
I don't think Mac even makes a 3" exhaust for the Mustangs. I'm pretty sure they are all 2.25" or 2.5".
__________________
Sometimes I think that government fits that old-fashioned definition of a baby: An alimentary canal with an appetite at one end and no sense of responsibility at the other.
- Ronald Reagan
I meant the tips like i put in the title of the thread. Both are 2.5" systems. But the choice of 3" or 3.5" tips. Im guessing it is just a visual thing. I think the Borla 4" is too large but i think the 3" may be too small haha. Are the stock GT tips 3"?
Stock GT tips are 2 or 2.5. The Mac tips are probably polished and rolled stainless. They look pretty sharp, I had a set on my 04 GT.
__________________
Sometimes I think that government fits that old-fashioned definition of a baby: An alimentary canal with an appetite at one end and no sense of responsibility at the other.
- Ronald Reagan
dont be afraid of the 4inch.i have 4 inch single wall angle cut tips that i really like.seem to go well with the 315 tires, looks very nice from behind.very few fart canons try to pass.
I don't think Mac even makes a 3" exhaust for the Mustangs. I'm pretty sure they are all 2.25" or 2.5".
Hmmm, I have a Mac catback that is 3". And the tips are 3.5". I think they fill out the exhaust cut outs perfectly. No rice at all. Now that I have them, mustangs with stock exhaust lok like they have straws poking out the back of the car.
__________________
C&L 80mm mass air and True Flow pipe, Mac CAI, BBK 65mm tb, Steeda non-piggy back ud pulleys, MGW shifter, RAM HD clutch and aluminum flywheel, 3:73 gears, 2.5" Dynomax o/r x pipe, 3" MAC cat back system w/ 3 1/2" tips, Kenny Brown(front and rear strut tower brace, caster plates, subframe connectors,extreme matrix brace,jacking rails, torque brace, lowering springs), Tokico D-Spec shocks, 03-04 Cobra(side scoops, rear bumper cover, top), 6pt roll cage, white FR500's, FMS 2000 Cobra R air dam.
MAC Catback 3" vs 3.5" Tips 
.. Think a bit dude...
.........Ok anyways. Mac makes awesome catbacks. If your talking about a 3" "CATBACK" and not 3" tips.. then it would increase performance atad. if your talking about tips. then i THINK 3" and 3.5" just have visual differences. somone else would probably have more input.. id definatly go 3.5" though 
