I just finished installing Stainless Works Long-Tubes with Hi-Flo Catted Y-Pipe on my truck. The quality of these pieces is incredible. Perfect welds everywhere. Both sides went in super easy. Used new GM manifold gaskets and used the stock bolts. I change my plugs to ACDelco Professional Iridium while I was in there as I noticed my stock original (33K miles) had a gap of about 0.055" which is 0.015" more than spec. The Y-pipe was a little tricky to get on but it does fit well. The only area of concern for me is the "Socket" on the end of the Stainless Works Y-Pipe where it goes from (2) 2.5" pipes (with cats) into the 3" transistion piece that attached to cat-back(or stock exhaust). The "socket" is too small for the "ball" on the intermediate pipe of the MagnaFlow cat-back system. I cranked the flange bolts pretty tight and so far so good. I do not have many miles on it right now (maybe 10 or so) but it seems very different. Torque seems improved throughout the rev range and the sound is not much different than stock manifolds, cats, Y-pipe with MagnaFlow dual outlet cat-back. It is just a little deeper while accelerating and maybe a hair different while crusing. Just thought I would give my experience (albiet a short one so far) Any questions please feel free to ask. Whats next?!?! More than likely a dyno-tune and then electric fans.

 

We need pics!

 

Congrats man, that's good news...I'm looking forward to doin mine when I have a second to breathe....(things have been a bit hectic lately). Did you use any high temp RTV where the pipes slip together or just slide em on and bolt em up?

 

useless without pics

 

I'll try and get some pictures tomorrow at lunch time (depending on weather). If not tomorrow then sometime over the weekend. Any pictures in particular? Bud, I used RTV only on the the driver's side header/cat slip-joint and on the passenger's side header/cat slip-joint and cat/intermediate slip-joint. I did not feel it was necessary to put it on any other because (1) the joints have pretty tight tolerances already and (2) they are after the O2 sensors. I think the RTV is just to take up the slip-fit tolerances so the O2 sensors can get as accurate a reading as possible.

 

Congrats on the install! Bet it sounds a lot better now!

 

The stock gap is 0.060". At least it is for '03 all engines.

Congrats on the headers.