I cut up a factory duramax exhaust for free 3.5" mandrel bends.

 

Interesting. Looks like a good fit too.

 

Yes, it is expensive. Spintech seemed to be the cheapest for what i was looking for but shipping was a bit steep. $20 for 2lb box. I ordered at 10pm last night and had a tracking # this afternoon. They didn't waste any time getting it out the door...which was nice i guess.

 

You don't "need" large exhaust. Stock48 was going 10s on 3".

I had 4" with 7" rear drop, requiring cutting the underside of the bed

 

You may remember when I did the first project thread on my truck. At the time it was 100% factory suspension, but with the built driveline and blown iron 346" I was running a 4" exhaust for a diesel truck with a magnaflow over the axle.

The whole point of that first build thread was to document and do a 4/6 drop that would still pull good 60's at the drags. In the end, I had to cut the 4" right after the muffler and do a turn down as it wasn't gonna clear.

Just my $0.02

 

Thanks Travis. That makes sense.

I guess need is all relative... but i wouldn't install a turbo kit without a larger exhaust than 3". Just because someone made decent power without a it doesn't make it right. I'd be curious how much power he left on the table. Did he have a cut out? If so that changes the game of course.

 

I had a single 4" over the axle and dumped under the bed on the SSS but I was only lowered 4" in the rear at the most. I want to say that the over axle pipe was from a magnaflow catback, but i dont remember the part number.