I have been thinking about going to single 3 inch exhaust on my 460. It's in a 79 Bronco, I am thinking about going this route because the 2.5 inch duals take up so much space underneath. Am I going to be choking it down too much or can I make this work? Any suggestions, thanks in advance!
John

 

How much horsepower are you making?
What is your redline, and how often do you use it ?
What kind of headers do you have. (cast manifolds are more restrictive than almost anything downstream)
What other restrictions are there? (cat, muffler???)

2 1/2" headpipes into a large volume school bus muffler with single 3" outlet seems fine in my non-catalyst truck.

Dual 2.5" pipes would flow about the same as a single 3 1/2" pipe.
BUT, a lot depends on how tight and how many bends there are in the system.

How To Calculate Muffler Size and Exhaust Pipe Diameter | Exhaust Videos
There is a chart here that suggests that a single 2 1/2" pipe would support the ~220 Hp that stock 460's were rated for.
The single 3" is charted at almost 340Hp.
Dual 2 1/2" at 463.

Remember, that too much volume will allow the exhaust to expand and cool, it will lose velocity and you will lose scavenging efficiency.

 

It's pretty much stock with the current set up, over the winter I plan on warming it up a bit. I am adding an Edelbrock Performer RPM manifold, 750 carb, L&L shorty headers, mild cam, straight up timing, some mild port work, probably a couple ignition upgrades. I eventually want to build a stout 460 from the ground up, a build that will make good all around power and and hold up to a fair amount of abuse. The current one runs pretty healthy but it feels choked down in its near stock form.
The Bronco has a 6" suspension lift with 37" tires. I'm running a C6/NP205 combo, the D44 and 9" are loaded with 4.88 gears... the front has a Dana Power Lock and the rear has a full spool.
I'm not too concerned about fuel economy as this is more of a trail rig/mud bogger/dune truck. I'm just having a hard time deciding whether to go with dual or single exhaust, obviously performance and sound is very important to me. Thanks again!
John

 

I have a 75 F250 with a 460. Nothing special but C9 heads slightly ported with bigger exhaust valves, custom cam, 9.5:1 ish comp. Will be running the L&L shorties to 3 inch pipes into a single 3.5 inch Flowmaster 10 series. Might be a little overkill for now but will be good for a later motor and I won't have to rebuild my exhaust.

 

I'm running a 400 in my 79 f350 4x4 with a 4spd, 4.10gears and 38.5" tires. Motor has a 600 edelbrock with a performer intake and full msd ignition, stock manifolds and Y-pipe with 3" single into a flowmaster bigblock series muffler.

I'm very pleased with how it runs, pulls hard (lots a low end grunt) its not fast by any means but I think a good set of headers would help out with top end power and acceleration.

 

Sounds nice, any sound clips?

 

No, sorry no sound clips. I do know its much quieter than the 2-chamber flowmasters on my 460, that thing sets off car alarms at an idle lol!
the bigblock series is quiet but has a real nice aggressive sound and doesn't get obnoxiously loud when you get on it. IIRC the Bigblock series comes in a couple different sizes to fit your application in terms of the overall size of the muffler.

 

I had factory manifolds, 2.5" true duals, 40 series Flowmasters, and 3.5"x18" stainless tips on my 460. It had that sweet big block muscle car sound at all rpms. It wasn't super loud but would definately draw some attention when I drove by. Overall I loved the setup except for how much room it took up under the Bronco. I will stick with the duals if I have to, I'm just trying to search for other options. Any other suggestions?
John