I have tti 2in primary with a 3 1/2in collectr and a 3in exhaust should i leave it at the 3in or go to a 3 1/2 it it really worth the trouble and extra money thanks for the help henry

How much motor and what kind of mufflers are you using now?

I would say no...

3" should do just fine...

after saying that...on mine, since I have no exhaust yet...Im going 3 1/2" because I'm tapping into the collector...fender exit wells with 3 1/2" collectors that will have caps...

I use 2" TTI headers with a 3-1/2" collector. I went with 3" and the X-pipe setup out to my rear bumber and I love it. Dont know if it slows it down any from open headers as I have never uncapped it. But I just wanted to have a pump gas car that I can drive to the track and run 10's through the pipes which it does. Good luck , Ron

before I did that I'd just slap a pair of cut outs on it. Even if you don't go biggger you'll have an idea if it will help. Uncap then and run it. If you drop some et (which you will) then you have to decide if it's worth the cost. I have mine back not far from the muffler so they don't hang to low.

Well from what I remember you dropped the mufflers and gained .2 ET. I always tried to get the orig owner to put a better muffler on that car. Currently, I think they are some modified 'turbo' design? If nothing else some bullets in the same 3" should pick it up.

Right now it has a cheap sonic turbo muffler and an h pipe to the rear axle so maybe a dyno max muffler and an x pipe would be just fine and it did pick up 2 tenths with open headers.how about a 3" pipe with a 3 1/2" muffler wonder how that would work

I had a 440 1969 Dart that picked up .8 and 9 MPH by removing a set of 2.5 turbo muffs and sides pipes exiting in front of the rear wheels, I used a set of 14x7x3.0 inch oval Magna flow with three inch pipes from the 3.5 inch Hookerfender well headers on my pump gas Duster. The muffs. are mounted behind the rear end between the rear sub frames and outer 1/4 panels, it is nice to drive and only looses .04 ET and .15 MPH in he 1/8 mile when I've removed the complete exhaust sytem at the local track, probally the weight making the differences and not the flow restrictions, not worth removing for that little gain The Duster runs low tens(best of 9.993 at 134.5 MPH ) on pump gas, motor only with the air cleaner and exhaust on 3450 lbs with me in it

Well then a 3" system with an x pipe and a good mufflers is the way to go thanks for all help guys

3 OR 3 1/2 but I would use spin tech mufflers. THE BEST FOR SOUND AND POWER. http://www.spintechmufflers.com/ After you here them you will never want any other muffler!!!

what spin techs do you use dont want something to loud but would like a deep sound

I'd stay w/ 3" and get a straight through muffler like the dynomax ultraflow, hooker max flow, or magnaflow. You'll see more of a gain from swapoping mufflers than anything else. If you don't have an H or X pipe, get one. An X pipe makes more power, but H pipes sound better..just my personal opinion. I'd stay away from spintech mufflers.

Was also looking at the ultra flows in the 6" round 3"in and out insead of the ovals any difference between them two

I use the 3 1/2 race muffler. At WOT its like you are uncorked!! Maybe not what you want for the street.

all 3.5 tube.. with turn downs at the axle. w/big flowmasters

Yes the race mufflers are going to be way to loud i have run them on my cuda before so i think i will go with the round ultr a flows in 3" and dump them at the rear axle and why stay away from the spin techs???

Put a bung in the exhaust just in front of one of the mufflers and test for back pressure while under full throttle. Might show restrictions if you have any. I don't think the 3 inch pipe is a problem, but the mufflers may be depending on how good they are.