X pipe with 2.5 duals vs. Y pipe with single 3 inch

[92C1500]

My current exhaust on my 92 C1500 350 TBI RCSB is true duals from the manifolds back no cats with 2.5 piping into an H pipe and two Flowmaster 10 single chamber knock off brand dumped under the front of the bed.

I put this setup on the truck roughly 3 years ago and it wasn't stainless so saying it's rotten is an understatement. the two mufflers each have a hole the size of my fist in the back of them in the casing as well as the pipe that was attached to them where the dumps were has rotten and fell off. It doesn't sound the greatest haha.

So with part of my tax return I'm definitely picking up some Hooker Comp Longtubes with 2.5" collectors, but I'm undecided on what kind of pipe to run off from that. It will have no cats just like now.

Keep in mind, I'm swapping in a 350 Vortec with a cam, and a carb to replace my TBI.

I'm thinking either 2.5" duals with a Magnaflow Tru X pipe, into two 18" dynomax bullets dumped right before the rear axle.

Or

Flowmaster scavenger Y collector 2.5" in/ 3" out into a single 18" dynomax bullet dumped right before the rear axle.

I'm looking for the smoothest, tuned, exhaust note I can get.

I really like the way the LS series engines sound piped out, but I know firing order has a lot to do with that. They just have that fluid, smooth, almost exotic v8 sound to them. I'm just looking to get close to that tone.

My favorite exhaust setup I've heard on a truck is the system the Silverado RST and Sierra RST come with stock. All I know is they have JBA shorty headers, and dual tips coming out the back. Other than that, I'm not sure of pipe size, setup, or muffler style. I just know they sound mean.

What are your opinions? I'm looking for sound + performance.

[OutlawDrifter]

do you have something against going over the axle? both of those setups will drone terrible dumped under the box.

as far as flow, the single 3" will be fine with a vortec headed 350. it will take a lot of hp to need more than that single 3".

truth be told, the x and the y setup's will sound similar. an h-pipe will have a deeper sound.

no sbc will ever sound like an lq/ls platform. it's just not in the cards.

if you're questioning my credentials on the subject, my z28 puts around 425hp to the wheels. it runs the 1/4 mile at a traction limited 113mph @3660lbs. so i know the hp number is accurate if not lower than actual. i run 2.5" pipes off the headers to a single 3", over the axle to a crossflow hooker aerochamber. with the cutout open before the axle, the car only picks up 10hp. at the crank this car makes well over 500hp.

a single 3" on your pickup is not only cheaper, but will flow plenty for your setup. the 18" bullet will be deep, but if you want a more "smooth" sound, the ultraflow is what you want.

my pickup will soon be getting the flowmaster merge and an ultraflow. it currently has a 10 series(previous owner installed) on it that is just too much, it was considerably better when i put a tailpipe on it.

[92C1500]

I don't have anything against it, I've thought about dumped over the axle too. I like the look of no pipes sticking out. Looks cleaner to me. Would over the axle reduce the drone more?

As far as not sounding like an LQ/LS I know that's not really achievable, I just like their tone. I supposed I could do a 4/7 swap cam which would get it closer to LS firing order.

It is good to know that X and Y will have similar sound, and performance for what I want to do. and you're right the Y will definitely cost me less.

I have looked at the ultraflows but I'm not sure how loud that would be compared to the bullet. I'm thinking quite a bit quiter. I do like an agressive sounding exhaust.

I was looking into the 18" Dynomax bullet because dimensions wise, and muffler style with the single 3" setup, it's appears to me to be close to an SLP bullet which they use on the loudmouth setups on the F bodies and they sound pretty good most of the time.

[OutlawDrifter]

Originally Posted by 92C1500

I don't have anything against it, I've thought about dumped over the axle too. I like the look of no pipes sticking out. Looks cleaner to me. Would over the axle reduce the drone more?

anytime it dumps under the box the sound will resonate in the box. you need to get the sound away from under the pickup. i don't like a big show of tailpipes either, i generally keep them tucked but make sure the sound waves find themselves exiting away from the vehicle. you could run the tailpipe to the corner with a turndown and that would help some.

[Tom]

The duals will flow more, the single will be more smooth sounding.

[LostMy65]

Oops, wrong thread.

[Timtruck]

I have a single 3", or did have, over the axle and it sounded good. After lowering it the tailpipe is kinda big for the smaller area, so for now it's dumping just at the rear of the cab and the drone is really bad!, I might route it out the side but the 3" pipe is kinda big and would be really close to the ground...