flowmaster single/single

akshay · June 18, 2004

For a flowmaster muffler, is 2.5" pipes (w/ single side-exit ) good for my truck?

The muffler is a single/single (in/out).

Should I get a 3" pipe before the muffler? Or keep it 2.5" before and after the muffler?

citydriver · June 18, 2004

I could be wrong, but I think the stock pipes are 2.75" (2-3/4)...at least thats what they are on my '95 5.7L...I have a Flowmaster 50 series on mine using stock pipes.

I needed shims cause the muffler has a 3" in and out,then I used stainless band clamps ...they cost more than regular exhaust clamps (about $8 at NAPA) but seal better...no leaks or crimped pipes

It sounds pretty good for a BUDGET exhaust...just my opinion

LikeaRock14 · June 18, 2004

For any single application on a small block 3" in/out is fine

Mort · June 18, 2004

For any single application on a small block 3" in/out is fine

I have a question. If your pipes are 2.5" ID say about 2.75" OD and you buy a muffler with 3" ID in/out how do you make up for the .25" gap around the pipes? Would it not be better to buy a muffler with 2.5" ID in/out and weld it up to the existing pipes?

Thanks

03GMCinBC · June 18, 2004

I have a FlowMaster 50SUV on my ride and it has 2.75 with 3" in and out. The muffler shop accomodated the pipes with a reducing coupling before and after the muffler. No leaks and it sounds great

akshay · June 19, 2004

Today the GMC dealer told me that my truck has y-pipe/cat from a 305cid. So, right now, I have a single cat setup. My flowmaster muffler is a single/single.

The dual-cat setup is $500 at the dealers. So I guess I have to get a new flowmaster muffler (dual/single) too...or maybe a dual/dual.

anealysr · June 19, 2004

Mine came with duel 2.25 in and single 3 in out. Now I have a Flowmaster 50 series duel in/duel out Both 2.25 in and out. with 3.5 inch chrome tips.

383S-10 · June 20, 2004

I also have the 50 series dual in/dual out SUV Flowmaster muffler......it sounds great. I get compliments all the time on the sound. My exit pipes are shorty turn downs at a 45 degree angle in front of rear axle. My truck is a 98 GMC Sierra X-cab. I love the sound I have medium loud.