I picked up a pair of Edelbrock TES headers for 65 bucks at a swap meet and I want to put them on my car, but what would be a good exhaust system for my engine? I dont care about the cat, although I would like to keep it, but I can remove it to save money if needed. I was thinking of getting a local muffler shop tp fabricate me a y-pipe which has 2.5" down pipes, then goes to single 3" pipe, then a 3" cat, with 3" al lthe way back to the muffler, then either dual 2.5" or dual 3" tips. I kinda want the exhaust tips to come out like a 5.0 mustang where they are really far apart, and run right below the quarter panel. Has anyone done this? I think I would have to cut out the bottom of the spare tire well and weld in a flat piece, because it hangs down pretty far. Anyways, any input would be much appreciated.

 

On a 400, I would try something like duals like No4NJunk.

Why do you want to have a 2.5" y-pipe??
How much power is the 400 puttin out?

 

I have a 406 with 1 5/8" hedman shorty headers...with seperate downpipes for each that join using a flowmaster Y (dual 2.5" into a single 3") then single 3" tubing all the way back to a single Hooker Aerochamber muffler and a single driver's side outlet...I like it...basic and people think I "must" be slow cause of the single 3" outlet

Ditch the Edelbrock headers BTW, I have heard what a restriction they are and seen some pics to back it up...check out the welds on the inside for proof.