cool, thanks. It looks like that works rather well.
CK5
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exhaust suggestions?
- Thread starter ashman
- Start date
Just got off the phone with walker and unfortunately this pipe is 2" into 2-1/2".
Is this for the 6.0L? Will the flanges still line up in the same spots?
It did go back in easy enough. Plus you can flex the pipes a little if needed so it doesn't have to be 100% exact.
No, it's not for the 6.0. I'd have to modify it but judging by what I got from the junkyard it would be pretty close. I already have 6.0 flanges so if I could find a y-pipe with 2-1/2" down pipes I could probably marry the 2 fairly easily.
Yeah, seems like that shouldn't be too hard to manage.
Hoping to do a 6.0L swap myself so that's why I was curious.
Hoping to do a 6.0L swap myself so that's why I was curious.
I'll document as many issues as I can.
Thanks. Make sure it is all exactly the way you want it when you come to Blazer Bash because I may be crawling all over the truck looking at how you did things.... 
Great, so if I cut corners I'll get busted huh? Lol
y5mgisi
1 ton status
Just measured my oem one. It's 2-1/4 also. Would one from a 454 be 2.5"?
Nothing I could find oem and drivers side was 2-1/2. 
4xcrazy
3/4 ton status
I'm not too positive my OEM one was 2.5" either, those looked a bit smaller. Not sure why they would need to be that big with only flowing 4 cylinders.
It's the meeting place switching to 3" I would be more concerned about.
It's the meeting place switching to 3" I would be more concerned about.
My 6.0 came with about12" of the stock exhaust pipe so that I would have the first oxygen sensors. The pipes are 2-1/2.
y5mgisi
1 ton status
What about 89-91 crew cab 4x4 with 454?
I have another question. How much of a difference does mandrel bent pipe make over standard bends?
I've been researching building my own y-pipe. I'm assuming that the difference between using the 2-1/4 pipe I have and going to a 2-1/2 pipe is significant enough to make it worth the effort. (tell me if I'm wrong) What I'm less sure of is whether mandrel bent pipe is enough better to make it worth the cost. It looks like I can get all of the regular bent stuff I'd need from o'reilly's locally at about 1/3 the cost or cheaper than buying mandrel bent stuff from summit.
Is mandrel bent stuff really worth 3x the cost at the hp level I am running?
I've been researching building my own y-pipe. I'm assuming that the difference between using the 2-1/4 pipe I have and going to a 2-1/2 pipe is significant enough to make it worth the effort. (tell me if I'm wrong) What I'm less sure of is whether mandrel bent pipe is enough better to make it worth the cost. It looks like I can get all of the regular bent stuff I'd need from o'reilly's locally at about 1/3 the cost or cheaper than buying mandrel bent stuff from summit.
Is mandrel bent stuff really worth 3x the cost at the hp level I am running?
If you're going to be doing it yourself, mandrel bent pipe will be a lot easier to use. This is because the diameter of the pipe stays consistent through the entire bend. You may find you need to cut a bend and then rotate one part and weld it back together. If it's not mandrel, it will be hard to line it up without big gaps. Same problem if you cut part way into a bend and try to weld on a straight piece. The mandrel just gives you a lot more freedom.
As far as HP gains, I don't know how big a deal it is. I think the theory would be 2.5" mandrel bent is true 2.5" but the same pipe done with the cheaper bend style is more like a 2.25" diameter through that bend. At least that's how I feel about it.
As far as HP gains, I don't know how big a deal it is. I think the theory would be 2.5" mandrel bent is true 2.5" but the same pipe done with the cheaper bend style is more like a 2.25" diameter through that bend. At least that's how I feel about it.
y5mgisi
1 ton status
Just FYI, I think the reason the ls motors use 2.5" off the manifolds is they also use a cat off each manifold. So they probably stepped it up to compensate for that.
My plan is to use http://www.summitracing.com/parts/big-52525flt and http://www.summitracing.com/parts/flo-y214300 to make my own y pipe.
Then a http://www.summitracing.com/parts/flo-2900230 and finish with http://www.summitracing.com/parts/gib-315590
Should give me a nice mandrel bent 2 1/4 merged to a full 3 inch system.
I couldn't find anyone who does a mandrel bent y pipe for our trucks. Walker does a 2 1/4 to 3 inch y pipe but it is crimped and T's together for lower flow.
Then a http://www.summitracing.com/parts/flo-2900230 and finish with http://www.summitracing.com/parts/gib-315590
Should give me a nice mandrel bent 2 1/4 merged to a full 3 inch system.
I couldn't find anyone who does a mandrel bent y pipe for our trucks. Walker does a 2 1/4 to 3 inch y pipe but it is crimped and T's together for lower flow.
That makes sense. Everything that I could find that was earlier (that didn't have cats there) was 2-1/4 or smaller. Since I don't have cats there I probably would have been fine with 2-1/4 but I was able to pull it together with 2-1/2 so even better.
I ended up going with a 50 series flowmaster and building my own y-pipe by piecing together parts from a stock LS y-pipe. The details are in my build thread starting at post 601
