2.25 or 2.5 pipe on a HO 4.0

I am planning on fabbin an exhaust system with A Clifford header, Dynomax turbo muffler, and mandrel bent pipes all the way back. I've seen most companies supplying 2.25 head pipes with 4.0 headers. I was curious if anyone has used a 2.5 head pipe and 2.5 pipes back with any low-end torque loss. I am planning on extensive bolt-on/DIY modifications and a ported HO head soon. So I'm just looking for feedback if anyone has actually tried these two sizes, and has any reccomendations Thanks.

If you're gonna do all the external bolt-on performance mods plus ported head, go for the 2.5" pipe. The difference it'll make to low rev torque in this situation is very small so I wouldn't be afraid to do it. It'll certainly be handy if you decide to build a stroker later on.

Thanks, I appreciate the advice. I am currently working on the head. I found a good core at a local U-Pull-it yard for 25.00!! I am in the process of working the bowls, guide bosses, and reshaping the chambers to unshroud as much of the valves as possible. The exhaust valves are quite shrouded by the chamber walls, and the valve pockets are a mess. So, by smoothing it all up and getting the throat venturi the right diameter I should see some definite gains in that department. By the way, nice website! I've been watching it for a few years now. You've got a killer amount of good, hard to find info!

check out http://www.go.jeep-xj.info/ tells ALL about it

im going to be running the clifford dual output header with my 2.5" piping from the cat with no muffler next week, so i can tell you if there is much loss or not.

Are you going to be running dual 2" inch pipes off the header and down to the cat? I'm curious to hear how it works out! Is your 4.0 stock? Good luck.

FUNKYTEE5 said:

Are you going to be running dual 2" inch pipes off the header and down to the cat? I'm curious to hear how it works out! Is your 4.0 stock? Good luck.

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i actually dont kno what size the pipes are off the header. the only reason im getting it is because i bought a hedman header about a year ago and it cracked and hedman doesnt make them anymore. so baxter auto parts is offering the clifford as a replacement. :dunno:

http://cliffordperformance.com/catalog/57-2015_dual_headers_1991-03_4_0_-_242_eng__1699256.htm

There's the link for the specs.

Also, they have 2 bungs, 1 in each header, for an O2 sensor - are you able to order them with only 1?

How'd your install go, and how'd it affect performance? What's the rest of your exhaust system set up like (true duals all the way back, Y-collector, ???)?