Mufflers?

Have a 3/4 ton F250 Super Cab running Headman shorties and will be installing a new exhaust.

I have 2 choices that I am considering and using stainless for both.  Will use a Xtube in front of the muffler.

1. Complete over the rear axle and exit out under the bumper.  If I do this I do understand that the muffler is at the end of the system.
What effect does this have with the muffler at the end?  Would I need to add a muffler to the middle of the system?

or

2. Dump under the bed just short and in front of the rear axle.

I like the following 2 1/2" muffler.  Its stainless and and straight thru and costs about $40 each.

I have also read that a little back pressure is good.  That why I would choose 2 1/2" vs 3" all the way. Truck is for street and some towing not racing.



Bob
Tucson

If it were me and I was planning to use those mufflers I would point them down in front of the axle. If its to loud or has an undesireable drone to it, then you can add more pipe and go all the way back. With a longer system I like to keep my smallest restriction at the back I've had good results with my suburban and my yard truck doing that. Gives lots of time and space for the pulses to smooth out.

my yard truck 89 chev tbi 2.5" stack
suburban supercharged vortec 5.7 afterburner headers 3.5" single

First off, when I choose a muffler, I choose a muffler by it's flow rating. If a company does not rate it's muffler's flow rating, I will not use their product. For the most part, I use MagnaFlow mufflers because they are a straight thru, big case muffler and the packing they use is stainless steel. The stainless steel packing does not burn out like most others' fiberglass packing.

You did not give much information, but I am going to assume ( ) that the engine is a 460 gas engine because you are on this site. I am also going to assume ( ) that there are two gas tanks, one on drivers side behind the driver and one behind the rear axle. To dump the exhaust gasses in front of the rear axle is not a good idea for a few reasons, one of which is the hot exhaust gasses bathing the gas tank. Not to mention the corrosive influence of the hot exhaust gasses to the under carriage of the vehicle.

Also, we do not know the HP/TQ output of your engine, which determines the exhaust pipe sizing requirements. For instance, if you have a 400 HP 460 cubic inch engine, and you go to a 3 inch system, you will lose TQ with no or very little HP gain. Assuming ( ) your engine produces under 500 HP, I would go with a 2 1/2" system.

Usually, with the 2 gas tank deal, the driver's side head pipe comes off of the header and goes over to the passenger side of the vehicle where it parallels the passengers side head pipe. Before the two pipes exit in front of the passenger side rear wheel, the two mufflers are installed with the width installed vertical which takes up less width room. In the case of a large inch engine, I find that a "H" pipe works well and is easier to fit.

A straight thru muffler with a "H" pipe (balance tube) in front of the muffler and tailpipes behind the muffler produces an mellow tone.

429, 450 hp, fitech FI, headers, will be using a h pipe.

Just what I needed and always more to think about.

Yes I'll use the 2 1/2size pipes.

I'll be checking on the internals.

Thanx

Bob
Tucson