Thats why I added midlength headers. Thorley mid length ceramic coated ftw.

 

well if it helps talk to AJ. hes got a 6.0 with a cam and Pacesetters and he cant keep it straight to save his life. I think somethings wrong

 

I bet it's the no mufflers, you're feeling... JMO..

 

You and me both. Gained in every department 60foot included. And it was just a bolt on 5.3 w/3.42 gears.

 

picked up .1 60 ft and .2 1/4 on mine with a stock tune.

 

I bet its the 3.08 gears killing him, I just saw that in his list.

 

You need mufflers and gears IMO...

A 6.0L shouldn't lose anything with those headers anywhere.

 

IMO, your losing all your power from having no muffler. the headers are flowing alot better than the manifolds causing less backpressure. and with no muffler added you have no backpressure at all. beleive me me and my buddy with a silverado ss pull our mufflers off all the time to be loud and their is a huge difference in acceleration. muffler ads quiet a bit of low end with headers. im running an lq4 with pacesetter longtubes, offroad mid pipe and a borla xr-1 or a flowmaster 40 depending on how loud i feel like being. my crew cab HD was noticably faster after install of headers.

 

I was on my way to work today, and it started doing what it was doing when it had open headers. Felt like I was running on less than 8 cylinders. But as I continued to drive, it got feeling better. Still not good out of the hole, but better. I had a guy at work telling me it was the front O2 sensors, which with open headers, I had to unplug to make it run better. Also, when I pulled off the plug wires to put the headers on, one of them pulled apart from the boot, but I crimped it back on. I also told allen to tune for a 160 stat and I haven't put it in yet, so I'm not sure if that has anything to do with it. I thought I heard people talking about changing timing because of the lower temp.

I didn't figure these were a problem, but maybe I was wrong.

 

What does everybody think should be the optimal primary and collector size for a stock cam 5.3.