Hello I have a 1996 F-250 7.3 with a Ts performance chip and stock straight piped exhaust. I was wanting to start getting parts to put in stacks. My downpipe is stock and the straight pipe is 3.5". Is it recommended to put the bigger downpipe in before you put stacks or does it not really matter? Also any suggestions on pipe size. Thanks

 

Stacks are for semis, not pickup trucks.

 

Well... the point of stacks is to get exhaust away from the vehicle/machine/operator. Not everything can have it's exhaust routed out the side like a pickup... like most tractors, gensets, dozers, etc.

Is this for looks, or performance, or both?

If performance, I'd uncork the rest of the exhaust first. If it's just for looks... do whatever you want first.

 

This. I think stacks look terrible on pickups. But that's my opinion, you can do what you want with your truck.