Anyone running dual 40 series Flowmasters on a 350

[Zumo]

On their truck? I am getting ready to install my motor and I want to lose the glasspack setup I have. What inlet/outlet size do I need?

[patrolman808]

3" in/out would be good. You may want offset inlets depending on how you mount them.

[Terry Peerson]

I am running a 350, with 40-Series Flowmasters. 2.5" in/out. with an "H-Pipe". If you have a coil-spring truck, the 2.5" pipe is too big to run out the back. Unless you run it out one side (due to the Panhard Bar). I had mine stop right in front of the rear-end. Turned the bed into a big speaker. TOO LOUD! I'm going to change it to run out one side to reduce the noise in the cab. Someday.

Good Luck!

T

[70c10]

Inlet/outlet depends on what pipe size you will be using.

[BigSky71]

I ran two Flowie 40s on my 71 Cheyenne LWB, 2.25" pipe. My exhaust ran out behind the rear tires, no problem even with the 3/5 drop. I like the sound of that setup, not too loud at idle, really nice at 4k!

[yank]

I just had my exhaust put on my truck last weekend (350 sbc w/small cam). I ran 2.5" pipe from the headers to the mufllers (Dynomax Hemi's). had to use us 2 1/4" to go over the axle and and then ran them to the rear corners of the bumper. my entire exhaust is tucked up in between the frame rails.

[Zumo]

I plan on having them dump over the rear axle. Will that work?

[matthufham]

i have 2 1/2 in, 2 1/4 out. i then reduced the outlet to 2 inch because that's the size of the extra pipe i have around here.

[72MARIO]

For you own good. Do not dump it under the box. Get it outside of the body out back infront of the wheels. Unless you like not being able to hear yourself think then dump it under the body.

I have 3" dual Super 40's. It was dumped under the box and with the windows down it way loud but oky. Once it got cooler it drove me nuts with the windows up. I ran the exhaust out in front of the wheels and it not only sounded way better but I could cruize with the windows up and hear my radio.

[Bowtie67]

Unless you are running a hypo engine the 3" exhuast is a bit much as well as loud. I would go 2.5 and some type of H or X pipe. Mostly it is going to be how load you want it and if you cant stand the noise. You can go up to thir sight and click on their mufflers for sound comparisons.

[hilljob26]

i have dual hexhaust w/ headers and mine dump out the bottom right before the axle,it is 3 in 3 out,and they sound awesome,not too loud,but i also have spray-in bedliner all under my truck and in my truck,i dig it,and it is even tucked up in the frame rail so you dont see anything from the side,kinda a b1tch w/ that dang transfer case.mike

[speedracer]

I've found that most of the cars and trucks that I put flowmasters on tend to make alot of noise at the muffler not all at the tailpipe getting the mufflers farther back seems to work better as far as interior sound.

[Zumo]

Well I am not to concerned about noise right now. I have no radio. I sort of want it a little obnoxious. Sooner or later I will quiet it down a bit.

[cableguy0]

im running 2.5 in and out dumping at at angle in front of the rears. the mufflers sit right about at the edge of the cab on the back and have a 45 degree elbow with about 2 ft of pipe on the end of that. sounds really good. much quieter than when i had them dumped behind the cab.it will surely still wake people up when i pass em on the highway

[Zumo]

Thanks guys. I went with some mufflers from Summit. I am on a budget so those worked out great from me.