I am working on installing my dual exhaust system on my 1967 F100. I have blackjack headers and just bought a set of Flowmaster 40 series. I am trying to run the exhaust out in front of the rear tires. My question is how close to the driveshaft can I put the mufflers? Also I can get more clearance for the mufflers if i run the exhaust straight out the back but then i would have to run the pipes right under the gas tank which i am mounting between the frame rails under the bed. Will this be a problem running the pipes so close to the gas tank? Thanks in advance for the help.

 

To get more clearance with your flows, you can turn them up on their sides, either straight up and down, or at an angle. I would try for at least an inch of clearance, if not more. Why can't you run the pipes around the gas tank? I have a spare tire between the frame rails, as do many people. The pipes go around the spare. I would not run the pipes in front of the tires. It gets old really quick, having to hear this over your tunes all the time. I always run the muffllers behind the cab, underneath the bed. This keeps the in cab noise to a minimum.

 

I originally wanted to run the pipes straight out the back, i just like the look a lot better but didnt want the pipes that close to the gas tank so i thought to run them in front of the rear tire. Will the heat from the pipes be a problem if they are close to the gas tank? I dont want to blow the rear end off my truck. i would like to mount the mufflers under the bed and the pipes straight out the back if the clearance issue with the gas tank isnt a problem.

 

Ever put your hand on a tail pipe? Warm, but not very hot. Just to make sure, as long as they don't come into contact with each other (would make a noise anyhow) you have no problems.

 

If you want a before the tire side exit, I'd suggest a dual exit on the passenger side. Having the exit on the drivers side gets old fast. Constantly turning off the truck at drive up windows etc.

 

Good lord...I'd make the person in the driveup go deaf. Course..when McDonalds forgets my drink next time I could give them something to think about for a LONG time ^_^