I have a 98 Ext Cab F-150 with flareside. My exhaust manifold is rusted out and I plan to take advantage of this to replace it with hedders, high flo-cats and a magnaflow cat back kit. I want the exhaust to exit behind the wheel but not out the rear since I tow with a stock class III hitch. I would welcome any feedback/ideas/suggestions related to this. I am new to the mod world. I am looking to increase performance and gas mileage without losing towing/hauling torque. Sound is not a huge issue although I do like the sound clips for the magnaflow 15609.

I have not seen any posting related to installing a magnaflow cat back on the flareside. Any special issues?

Anyone using the gibson hedders?

What is SI/SO and is it what I want for this application?

I am also interested in your thoughts on a throttle spacer and the K&N aircleaner.

 

OBDecks, I had a 98, f-150, EXT, 4X4 flairside, had the 4.6L. I instaled a flowmaster Single Inlet pipe / Single Outlet pipe (SI/SO) 3" coming out the pasenger rear, wth a 2 1/2" tyed in at the axle. both exited straight back next to the frame rails and they did not bother my hitch at all

as I indicated above SI/SO, SI/DO, DI/DO is a abreviation for the type of muffler, Single In/ Single Out or Dual In / Dual Out

the single 3" gives better towing performance but the dual 2 1/2" look cooler. you can have the tail pipes exit at any point if you go to a good muffler shop. call around and do your home work on line. you should be able to find what your looking for.

 

I wouldn't use anything Gibson if I were you.....They are cheap....their customer service is garbage, and their parts don't fit well. Headers in particular you want to fit like a glove.....Don't make me say I told you so.....save yourself the headaches