Need help with Stacks

[Chevyboy_0]

SO i recently picked up some stacks off an old Pete and I am curious how other people have hooked them up. From what I understand the stock manifolds are 2.25" and I need to go from that to 5" and im not sure if I should try to make a smooth transiton or if on the exhaust side i dont need a smooth transition?

 

[redneckaggie]

you wont need a smooth transition ie a reducer from 5 to 2.25. the easiest way to do it is cut the exhaust and weld a y in in a convenient area ahead of the stacks. route from the y to the stacks with flex pipe of any size you chose( biggest i have seen is 3.5)- availible at an exhaust shop or area parts house.the easiest way to reduce down to the smaller pipe from the stacks is to weld a piece of plate onto the bottom of the stack with a hole in the center to fit the smaller pipe.

 

[punkmechanic]

I just take the larger pipe and cut notches in it. then hammer it down to the size you need (i used a scrap piece of the exhaust I was junking) and then cut your overlap and weld it all up. you could then clean it up a bit with a grinder or just put it on.

my rig has a 2.25 or 2.5 inch down pipe that goes straight into 5 inch that runs under the cab then up through the bed into a 5" y and out to 5" stacks. sounds good, just dont like the mess in the bed.

punk

 

[zigzkidz]

For mine i kept the 2.5 until under under the bed where to would go straight up. Then my bed pipe is all 5 inch, the 2.5 goes into the 5 under the bed, it looks like an L, with the 5 inch vertical and the 2.5 horizontal and then i put a plate on the bottom

 

[Diezel_Cowboy]

Y pipes are over rated all you need is to run the pipe into a box with holes for your pipes cut out.

 

[Agnem]

This was my old setup. I had modified an adapter to work with the smaller 2.25" pipe I had at the time.

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This is the newer setup, which is 3" pipe under the truck going to the stacks.

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[LCAM-01XA]

If I ever go with dual stacks I'd do like Jeremy (Pipeliner86) had on his truck - small pipe (2.5" or 3") T-eeing into a big pipe (5" or 6") positioned horizontally in the front of the bed, then the ends of the big pipe get capped, two new holes are cut on the side opposite to the inlet pipe, and the big stacks get welded onto the big pipe over these holes. Heck for ease of build I'd use a 4" square tubing instead of the big pipe, then I got flat sides to weld the stacks and the inlet on, and then I can build fuel jugs carrier on top of it too between the stacks.