5.3 swap y-pipe

[Jeepin Jeff]

Still gathering parts for my 5.3 swap into the J10 and have found a y-pipe kit offered by Jegs that I think would be a perfect option. Since my 360's single exhaust is nearly new from the cat converter back I am going to just add a y-pipe that will fit the 02 Yukon 5.3, remove the cat and tie it all together as single exhaust. What confuses me is they state "Fits all with OE 2-3/4'' single flat flange exhaust after dual converters only EXCEPT 2000-02 OE y-pipe systems with flat spot after driver's side O2 sensor and just before the y-junction". I guess I don't understand the significance of the flat spot and I don't have the original y-pipe to look at. I have seen other examples on here use the 5.3 and round pipe in that area, I would think it would work, if not I suppose it could be flattened easy enough. I would sure welcome thoughts and opinions, looks to me like an easy way to add a y-pipe with new parts that fit. http://www.jegs.com/i/JEGS-Performance- ... tId=758633 As always, thank you.

Jeff

[ProTouring442]

As long as it is returnable, I don't see a problem trying it. But I can tell you from experience, there isn't a whole lot of room down there. Also, it looks like it runs the pipe to the converter awfully high up.

I think you're probably better off making (or having someone make) the head pipes to meet your exhaust. That way, they can work around everything that seems to be in the way and still end up exactly where you want the y-pipe to exit.

[Jeepin Jeff]

I'm glad that you have replied as I was wanting to do something similar as you did on your build and I still think this my be a pretty good start. This photo shows what it looks like a little better, do you think the flat area would be critical? I don't believe it affected anything on your pipe, correct? I haven't checked yet and I will, but I would be shocked if I could get that built around here for under $200.

[ProTouring442]

I'm glad that you have replied as I was wanting to do something similar as you did on your build and I still think this my be a pretty good start. This photo shows what it looks like a little better, do you think the flat area would be critical? I don't believe it affected anything on your pipe, correct? I haven't checked yet and I will, but I would be shocked if I could get that built around here for under $200.

I don't know about the flat area, but I do know that the clearance between the transmission and the transmission tunnel is pretty tight.

I went and looked under my Jeep several times and tried to compare it to the picture. I think it might work, but I can't swear to it. As long as it's returnable, I'd say give it a try. But if it isn't, $200 is a big gamble.

[Jeepin Jeff]

Spoke to Jegs and it is returnable, as long as it's not cut up, welded, or damaged. I also went and spoke to 2 different exhaust shops here in town and neither can build that for $200, Think I am going to order one and try it. Should be able to bolt it on loosely and install the engine/trans and know pretty quick how its going to work or how much modifying it will take.

[ProTouring442]

Spoke to Jegs and it is returnable, as long as it's not cut up, welded, or damaged. I also went and spoke to 2 different exhaust shops here in town and neither can build that for $200, Think I am going to order one and try it. Should be able to bolt it on loosely and install the engine/trans and know pretty quick how its going to work or how much modifying it will take.

Sounds like a good idea. Wish you were closer, I would have helped you weld up a Y-pipe like I did mine. Still, $200 isn't a bad deal at all, even when you add shipping.

[ShawnQ]

Subscribing to see how this turns out.

What manifolds/headers are you all running? I have factory manifolds from as n 09 truck. Trying to find definite info about whether or not they will work. Some say they dump right into the frame.

[ProTouring442]

Subscribing to see how this turns out.

What manifolds/headers are you all running? I have factory manifolds from as n 09 truck. Trying to find definite info about whether or not they will work. Some say they dump right into the frame.

I used the factory manifolds that came with my '08 LY5 (5.3) with little difficulty. Run through my build and you can should be able to see how they fit.

http://www.fsjnetwork.com/forum/viewtop ... =12&t=1850

[weezy]

What manifolds/headers are you all running? I have factory manifolds from as n 09 truck. Trying to find definite info about whether or not they will work. Some say they dump right into the frame.

My 5.3 is out of 1999 silverado and the driver's side manifold dumped right into the frame. I am not exactly sure what year they changed the design to the tighter manifolds but I am going to guess that it was 03. I tried to buy some used F-body manifolds off of ls1tech and narrowly escaped with my money. The classifieds on that site seem to be a haven for scammers. The used junk yard and ebay F-body manifolds were up over a $100 so I did what several swappers decided and popped for the LPP shorties. I haven't solved my Y-pipe problem yet so I am eager to see how this Jegs experiment comes out.

[Jeepin Jeff]

What manifolds/headers are you all running? I have factory manifolds from as n 09 truck. Trying to find definite info about whether or not they will work. Some say they dump right into the frame.

Mine are from an 02 Yukon and look to me like they dump just about like the original 360 manifolds, I think they will work but won't know for sure until I get the pipe and actually do a little fitting. I am pretty excited about the y-pipe, I think that for $200 shipped with 02 bungs and mandrel bent pipe its pretty hard to beat, if it fits....

[nester]

Keeping an eye on this, since I don't think my long tube headers are going to fit...

[weezy]

Hey Jeff - Did you get the Y pipe yet? If so, how is the quality and fit?

[Jeepin Jeff]

Yes, I did get it. The quality is excellent, its nicely made and it fits the engine fine but I am still not sure what I will do with it. I like the way many of the custom y-pipes actually run down and then between the flywheel and the transmission pan, this one doesn't. On the drivers side it goes down, straight back and down the side of the transmission and then makes a 90 right at about where the transfer case adapter is. This may or may not work with the drivers drop 241, I won't know for sure until I get the engine mounted and the transfer case mocked up. I think it will be very easy to cut and modify it to configure it the way protourings is done if I decide to use it.
I will get pictures added when I get a bit farther down the road.

Jeff

[weezy]

Hey Jeff - I am hoping that you are further along on your exhaust work than I am. I have the Jegs Y-pipe installed in my Waggy and plan on putting a cat behind it. The problem that I am having right now is finding the right flange to weld to the cat to bolt up to this y-pipe. The bolt spacing is much wider than the typical 3 inch diameter flanges. Have you been able to find that flange or did you just cut it off? thanks!


EDIT!!!!

I just found your build thread. Did you just cut off the flange and weld your existing exhaust pipe directly to the new Y-pipe? Or are my eyes fooling me in that last pic of your exhaust and there is a new pipe with the correct flange in there?

One last question.... what air intake are you using?

Thanks again.

[Jeepin Jeff]

I cut mine off weezy. My original cat had been welded onto 3" exhaust tube (no flange). I cut the pipe about a foot ahead of the cat when I removed the old 360. I ended up cutting off the Y-pipe flange and after squaring up my original cut was able to use an inexpensive 3" to 3" adapter from oreilly's. I welded most of it back together with the exception of one clamp at the end of the Y-pipe to tie the whole thing together. Couldn't be more happy with how it all turned out and most of it is new including the muffler. Hope that helps.

My engine swap is for the most part done, I have now just finished stripping the cab and front end down to bare metal and have it ready for 2 nice coats of SPI epoxy and then SPI pure white base and universal clear, hopefully within the next couple of weeks!

20140513_203239 (Medium).jpg

[weezy]

Thanks Jeff. It looks like I am going to have to do something similar because i can't find the flanges on-line. The guy that I spoke with at Jegs thinks it is a GM specific flange. I found a few threads in GM truck forums with cracked flanges complaining about how they couldn't buy just the stand alone flanges.

And just on your air intake.... is that one of the ebay intakes? Happy with it? I am planning on directing my air filter toward the driver side of the engine bay and moving my radiator overflow tank to the passenger side. If I am going to cut up and adapt an intake, I would rather do it with an inexpensive one.

[Jeepin Jeff]

I did buy the intake from ebay, it was used (take off from LKQ) but in like new condition and included everything including the Maf sensor. I'm not sure what brand it is but it is a pretty nice setup and was much cheaper than buying a new setup and worrying about cutting it. I thought about moving my battery but after looking it over good I just decided to leave it alone and cut the intake tube as others have done. I will have to shorten it just a bit more and it will be perfect, almost like it came that way from the factory!