The LT header question has been answered, but what about the Y pipe. I don't want to spend $600 on the Dynotech (although it is a quality piece), but I want cats and functioning O2's. Any suggestions? Welding is not a problem so what has everybody come up with?

 

Well if the stock OD is ok with you try a salvage yard for a lucky price on an 05 or newer y-pipe. The 05 truck cats are the same as vette cats. At least on my "B" L33 5.3 motor.

Perhaps you can cut and weld it to suit you. Put bungs in your collectors for precat o2's and weld flanges on the cats. You may be able to salvage the y or the y-collector but a good muff shop would be cleaner maybe.Here is a pic of my 05 cats. Rockauto sells them new for $439.00.

Find a u-pull it junk yard?

 

Take your factory y pipe and have it modified by a muffler shop.

 

+1, cut up your y-pipe and use that. Any GOOD shop can do it. And your headers you order should come with front O2 bungs. You may need to try and keep the old bung in the y-pipe if the threads arent all welded up, judging by how new your truck is, they should be ok