i have a 1991 f250 with the 7.3L idi and i was wondering what to do withthe exaust system i have it is all stock execpt the muffler fell off when i bought the truck and instead of messing around with the whole thing venting it to the back i bought a 90 degree elbo and vented it out the muffler to the front of the rear wheel. i was windering what size to do? headers? i do want to do stacks though i was thinkin 5" miter cut turnouts. any suggestions? thanks tim

 

stans headers does make long tube headers for them. 550 for both.

3 inch is as big as it needs to be, but bigger wont hurt. i am runnin stock y pipe into custom adapter to 4 inch into my stacks.

 

Would a 3.5 inch hypermax exhaust sound good on my 6.9 non- turboed engine?

 

In all reality stacks are preference just like any exhaust system. If you do a normal exhaust you can put a 3" or a 4" or 5" and it doesn't make a difference, UNLESS you are putting down a lot of horse power you will have to get a bigger exhaust for more than 450hp from what I have heard. But on the stack sizes, 5" are more than suitable. Hell I have seen people that have 6", 7", and even 8"!! It is all preference so anyway you are looking to go Im positive you will be fine. As for your headers question, I don't have any knowledge on what that means so I won't say anything to possibly lead you in the wrong direction