Any way to get 4" DP in an OBS?

[jeremie444]

Ok so like the title says is there anyone out ther with a 4" DP in thier truck, and how much modification to the body did you have to make?

Im having trouble pulling the 3" exhaust downpipe out right now.

From what I have read 3.5" is the maximum you can go. I'd like to try and fit a 4" custom setup in the truck and I figured while I have the transmission out it would be the perfect time to enlarge the area in preperation for a 4".

[kramarj]

Why do you want a 4" down pipe? That would be soooo much work. A 3" dp is hard enough to get in. It would be easier with the tranny out, but still.

[01Crewcab7.3]

Unless it is a really high horsepower truck then there is no real need or advantage for the 4" down pipe. I have seen plenty of 400+ hp trucks with a 3" or 3.5" down pipe.

[desertdeer]

a body lift and some serious time with a porta-power will git-r-done. but like others have said its a lot of work for very little gain. post pics if you attempt

[NorcalPSD925]

3in is plenty for a 7.3. no need for 4in.

[baderic03]

I make over 400rwhp and have a 3in dp

[terryknight]

yep a body lift

[atvrider93]

When I do it I'm gonna go for a 3.5" DP, I just need to figure out where to get one. I know it's been done.

[jeremie444]

ok then I guess im gonna stick with my 3", I had read a long time ago that the best exhaust after the turbo is no exhaust. So I was figuring that a 4" or 5" would have been best but if theres not much point then I wont try and strain myself to get a bigger downpipe when theres not much to gain from it. Maybe i'll just open it up enough so I can pull the down pipe out easier if it's ever needed, if i can open it up at all.