3.5 inch downpipe

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Aug 7, 2009 | 05:18 PM

TheTowingCowboy

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Fleet Mechanic

Joined: Mar 2007

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From: Meigs County Ohio

3.5 inch downpipe

Well early I had let people know I had gotten a bunch of free exhaust piping from the local bus garage. Well I was wrong, I measured my 'new' downpipe and it was 3.5 so I made the exhaust and used my old cat, cut the end off and made it so it goes from 3 to 4 inch, so my question is, Can I fit 3.5 pipe in my truck or would I need to want and get a aftermarket pipe? Cause lol I am poor and like to weld so the less I have to spend the happier I am.

OT: Also I still got a ton of pipe I will sell cheap, or trade stuff for. I am not wanting brand new things or want 500 dollar stuff for the pipe, just stuff. I am looking fro a newer water pump (Mine weeps so I have to put water in it). But anything goes and if you want to buy somme off me, I will make you a deal on it.

Aug 7, 2009 | 07:47 PM

yoslick

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From: NW Wisc

Good luck shoving a 3.5 in your truck, most 94-97's will barely take a 3" because 3 out of 4 motors are just a tad closer to the firewall due to wierd motor mounts on the frame and need the fire wall either porta powered out of the way or take the spot weld seam off with an air nibbler! 3.5 can be done but it's a real pain!!

Aug 7, 2009 | 10:08 PM

oldbird1965

Fleet Owner

Joined: Aug 2004

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From: AZ

I laided in the snow with a porta power and did some serious body work to get mine in. I read on here years ago that there isn't anything behind the firewall that you can hurt so I bend the sh.. out of mine but its in there. I've heard of 4" going in but I can't imagine. (I don't know if that sounded right? lol)

Aug 8, 2009 | 02:00 PM

RÖENTGEEP

FOREIGN GURU

Joined: Jul 2006

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From: Celaya, Gto. MX

And as I suppose, you would need to put a reducer between the 3.5 " pipe to the EBPV, wich is 3" IIRC. I think thats the reason that most of the down pipes are 3 to 3.5 and the others are 3 to 3.5 to 4", all depends of the pipe after the DP.

Aug 8, 2009 | 04:30 PM

TheTowingCowboy

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Fleet Mechanic

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From: Meigs County Ohio

So there is nothing behind are fire walls we can mess up if you take a... porta power (What the world is that? Is it a sawsall like thing?) to it? Huh.. I would so do that to put the 3.5 DP on. So ummm.. pictures of you guys cutting the fire wall so I know how to do it if I ever go to do it.

Aug 8, 2009 | 05:15 PM

yoslick

Elder User

Joined: Aug 2005

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From: NW Wisc

You don't cut the fire wall out of the way you bend it in towards the cab interior, a porta power is a hydraulic press kinda like the jaws of life the fire dept uses.. what ya wanna do is trace out the path the pipe is gonna take and bend a ditch or pathway from top to bottom into the fire wall for the DP to follow, big thing is to leave plenty of room because if the DP touches the cab firewall or back of the motor it will vibrate like crazy and that means lottsa noise!! it'll drive ya nuts!!

Slick

Aug 8, 2009 | 06:27 PM

oldbird1965

Fleet Owner

Joined: Aug 2004

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From: AZ

The porta power, I think of as the opposite of a pair of vice grips, instead of squeezing it pushs out. I used boards against the motor and trans to push against. I pushed and then put the pipe up there and if it was close I would try again.