Help me build my exhaust!!!!!

[azcat]

Ok I have searched through a bunch of the exhaust threads but haven't found any that answer my exact questions.

Here is the deal, 74 Jimmy stock engine only upgrade is HEI (not that that will have any impact on exhaust). I am not running headers just stock manifolds. I will never be running headers or trick out the engine so it will always be very close to stock.

What are the suggestions for a exhaust set up. Mine is shot and I am finally getting around to replacing mine. I will have it done at a shop here in town that does all mandrel bending and all that. So should I run 2.25 all the way back, 2.25 to the muffler then a bigger pipe from the muffler back or go 2.25 duals or what?

I am looking for the best economy and not loosing any low end torq etc. Any help would be great and thanks in advance.

 

[K85 Octane]

simple 2.25 y pipe to 2.5" pipe, single in single out muffler, to single tip. Cheapest, easiest routing, and good performance for a stock engine.

 

[diesel4me]

On my trucks I have just made my own exhaust most of the time--mine sit more than get used and as a result I get a short life out of stock exhaust systems,so I made my own...I found those 45 dgree elbows sold at parts stores work well on the passenger side off the manifold,and a 90 degree elbow works great on the drivers side--from there I ran straight pipe back past the t-case (which usually needed a custom bend to do so on the drivers side,if not both--I had a friend who does custom exhaust work so I had him bend me the pipes up)................................................................................................................................................................................................................For the mufflers,I used glasspacks or Walker "Royal Scot" mufflers that had the same thick shell,they last 5+ years,or I'd get AP "Silentone" mufflers or one of their "MSL" (Muffler Shop Line) mufflers,those have very thich steel shells and last a long time...if I ran tailpipes I often just ran straight pipe up over the rear axle,it never moved up far enough to make contact with them,and I'd run them straight out the back,or use turn downs on my pickups,on my K5's I'd run the pipes out in front of the rear wheels,but some places refused to give me a sticker with them exiting before the tires...................................................................................................One truck I plowed with had the usual junk exhaust manifolds,with studs that snapped off every time I went to replace the pipes..I got disgusted with that scenario,so I took the 3 bolt flanges off an old y-pipe I had replaced off,and welded them to a 2" NPT pipe coupling,and I used black iron water pipe for my exhaust!!..it was crude,very heavy,but I never had to replace the pipes once in the remaining 5 years I had the truck either.....if I had too,all I'd have to do was unscrew the pipe from my custom threaded flanges,I slathered the threads with a lot of never-seize when I put them in,in case they did need replacing.....if I had used schedule 40 pipe,I bet the exhaust would outlive ME!......

 

[Deuling]

If you plan on keeping the truck a long time you could do stainless and never worry about it again. If not stainless at least aluminized. Otherwise one tip on keeping exhaust lasting longer is to never start the truck and turn it off before its up to temp. When you do that the condensation never has time to be evaporated and it just sits in the pipes and rots them much much quicker.

 

[folkenheath]

He lives in Tuscon, I don't think rust is an issue.

I would just buy a true dual kit, you can get aluminized kits for $130 plus mufflers, for manifold back or header back. Dynomax or Hooker both make these kits for pretty cheap for our trucks.

 

[azcat]

Thanks for all the replys......

Ya I'm not so worried about it rusting out. It's dry here in Tucson and I never run the truck for a short distance.

I just always thought duals were better but after reading and learning on this great sight I have seen many think a good single exhaust set up is just fine. So that's why I started this post to find out what single set up was better or/and get opinions on a good set home for a stock truck. I use it on the highway, pull a 16 foot trailer with it and use it as my hunting/4x4 truck.

 

[CherryK5]

dual 2.25 to a 3 inch y-pipe. Single 3 out to the tailpipe. keep it bare pipe. tips look... cheesy.

 

[76zimmer]

dual 2.25 to a 3 inch y-pipe. Single 3 out to the tailpipe. keep it bare pipe. tips look... cheesy.

For a stock 350, I would go this route as well!

For duals, stay with 2.25 pipes and some turbo, or similar mufflers...good sound, and compact.
The mandrel bending will help alot with the 2.25 pipes...if not mandrel I would go 2.5 pipes.

 

[meanboyjr]

simple 2.25 y pipe to 2.5" pipe, single in single out muffler, to single tip. Cheapest, easiest routing, and good performance for a stock engine.

Agreed. I run the same setup, except the Y goes to a 3" pipe and a Flowmaster.

If I did it again and didn't want to run duals, I would run the 2.25" Y to a 2.5", since the engine is stock and I think the 3" tube is a bit of overkill. And I would pick something a little more quiet than the Flowmaster 40.

Still, Y pipe to single is a good setup for a stocker IMO.

 

[azcat]

Just thought i would give a update on what I did with my exhaust.

I put new manifolds on and went with the stock Y-pipe to 2.5 pipe from the Y-Pipe back. It runs into a Magnaflow muffler and exits right behind the drivers side rear tire (just like stock).

It sounds really good, not loud at all and the truck runs much better now that the exhaust is solid no leaks. the old exhaust had cracks in both manifolds holes in tail pipe and muffler and was patched together with bailing wire.

Is the stock Y-pipe on a 74 2 or 2.25?