Exhaust setup for the OBS swap?

[Norcalz71]

in tryin to get my budget together for my 5.3 and/or 6.0 swap, im wondering what ya'll as running for exhaust setup? i would like to do it right the first time, from what i've gathered single 3" out the back will be plenty of pipe, so i plan to re-use my 3" in/out bullet its only about a year old. im mostly concerned with from the collectors to the bullet itself, everyone just running like 2.5" off the collectors into a y-pipe to cat to muffler? i would like to do it nice and have it mandrel bent the first time around, no makeshift setup to get it running and then upgrade later. just trying to get an idea of what i am looking at price wise.

thanks guys

[RedHeartbeat]

Stock Fbody exhaust manifolds and then an Fbody set of cats and pipes were what I used originally. I cut an pieced the ypipe together to fit the 92 and 93 trucks using a little additional tubing. I believe the pipe size was 2.25" on the ypipe. I used the 98 model stamped stainless steel exhaust manifolds.

[Norcalz71]

are the fbody manifolds necessary on the OBS swap? or will the truck manifolds fit as well? this is on a 4x4, btw, if that matters

[RedHeartbeat]

not sure on a 4x4, haven't done one of those. The fbody manifolds fit tightest against the block and usually give the least problems. I have used truck manifolds, too, but they are a bit tighter to work with.

[knute_gis]

I used the truck manifolds on 2wd and they work great.

Get the ones without EGR

[Wtfan18]

i used the stock 5.3 manifolds and completely build my exhaust from the manifolds to the muffler. the tail pipe was cut of a 98 z-71 that had a 5.7 vortec. fit perfect! the piping off the manifolds is 2.5 inch stainless pieced together and welded all the way till about 7 inches from my muffler. actually came out pretty decent minus my welding skills but ill clean them up a bit and just run them until lance finishes the LT's for our trucks. i could probably have a set mandrel bent but i really didnt care enough to try... as long as they dont leak and the motor breaths im happy.