I have a 1971 F-100 390 4x4 stepside. Going by the suggestions here I ended up going to a true dual Cherry muffler set up that I am pleased with so far. Now I need to run it from underneath the cab.

I have two choices:

1) Run dual stacks. The draw back is my exhaust is slightly smokey and I do not want it to blow back into the cab from the open slider or future sunroof. Anyone have problems with this that are running dual stacks? I can not have it exit straight up since I will have a ladder rack and will have to have it exit towards the sides. Is 6-8 inches above the roof line enough so it does not blow back into the cab? The main benefit for me is it will make it easier to create something that can ford 3 feet of water easily (up to 24 inches now).

2) Run the exhaust straight out the back and have it exit between the bed and frame. This ruins my plan for a rear axle tank since my exhaust has to be up in the frame to avoid being ripped off when off-road. Plus, I only have about 28 inches off the ground in the back.

Is there anyone that runs dual stacks that regrets it. Is blow back in the cab a major problem with the stacks being so close to the cab?

I planned on mounting mine near the outside rear corners.

 

I'd run them both down the passenger side and out in front of the rear tire. Get some mandrel bent pieces and have the exhuast shop do the rest.

 

I think dual stacks are the coolest and i think you should go for it! If you have it about the amount mentioned above the cab i dont think it will be a problem. i wish i had a truck, if i did. the first thing i would do is relocate the radiator to the bed along with dual electric fans and add smoke stacks! but theres me talking again! :-Blah

 

I would go with stacks too! I think they look good on a stepside and don't think the smoke would be a problem in the cab.

 

if you keep movin the smoke will be behind you anyway

 

Yepper, just dont rev it much at stop lights And spend the $$ for stainless, rusted stacks don't look very good