The Jegs y pipe I have is 2" down pipes then is 2.5" out. Does anyone know if there is a y pipe available with 2.5" down pipes and is 3" out? Or do should I have the exhaust shop make one.

 

For what its worth, I installed a replacement cat (Magnaflow Converter - 99047HM (dual 2" inlets, 3" outlet, front O2 sensor port) instead of a Y-pipe. The cat wasn't terribly expensive and I got a local muffler shop to cut out my old cat and weld this one in its place. Also went with 3" pipe off the back of the cat into a Dynomax UltraFlo Welded Muffler - #17233 and a 3" tail pipe. This system flows very well and sounds nice and mellow.

 

Right now I have this http://www.jegs.com/i/JEGS-Performan...31020/10002/-1 going into a magnaflow si/so hi flow spun cat them to a carven r series muffler, carven y pipe and duals out the back. The mid is 2.5" and my tail pipes are 2.25". It sounds great but am doing some more engine work this winter and want to go 2.5" down pipes from my headers, into a carven y pipe ( dual 2.5" in, single 3" out) then to my 3" cat, 3" mid pipe all the way to the 3" muffler then into another carven y pipe with 2.5" tail pipes.

 

Unless you are planning to install a stroker motor (408 cubes or larger), I suspect that you are going to kill your low end torque with those 2.5" pipes. I'd suggest staying with the 2" pipes, but not sure what mods you are planning on that would benefit from the larger head pipes.

 

Plans of boost, spring 2017 haha. More air in, more air out. Or should I stay with the 2" down pipes, do 3" mid pipe, cat, n muffler, and 2.5" duals?

 

Personally, I'd try it with what you have 1st. Would also love to see how you configure the boost setup. Are you going to buy a boost kit (turbo, supercharger, ??) or fabricate it yourself?

 

Custom single turbo setup. Nothing crazy for now, 10-12psi max.

 

Would love to see the project as it progresses. Please consider starting a thread and sharing some photos of the project's progress when you get around to it.

 

Boost is always good, I'm in for this build

 

Will do!