LS3 Swap 2003 Z71 Tahoe

[stagrlee]

Thank you sir. This is the stuff I need to see. Which balancer did you use and did your accessories from the 5.3 line up? I'll try to get a look at the oil vapor system you used. Please feel free to post up any other details you can think of.

I'm using the factory harmonic balancer. Wonder if that was a mistake on my part. Since I'm using a low RPM torque setup vs high rev, its probably not a big deal.

The 6.7L motor is the same block - just bored and and different crank/rods/pistons. So everything bolts up. The whole line of LS motors is plug-n-play swappable parts, that's why the Corvette valley cover can be swapped in. You can go nuts thinking about different intake, cylinder head, crank/rod/piston setups. I differed most of the thinking to Texas Speed and Central Texas Performance opting for factory cylinder heads as my wallet was getting drained...

Lots of writeups on the conversion. Can't find the one I followed, but they are typically called PCV delete or LS6 valley cover swap. This one is pretty good.

I didn't need to cut the block. I remember spending a bunch of time figuring out the tubing. The 180 degree U-Turn hose is need for the catch can to mount by the oil fill tube. The can captures about 4 oz of fluid every 5k miles. Don't remember if I plugged the valve cover vents. You can see there are still plumbed to the throttle body with a long tube going to the driver side valve cover. Thinking about it, it would be weird if they weren't plugged. Things got rushed toward the end of the build on this truck.

 

[stagrlee]

Ahh - the valve covers are the inlet and the valley cover is the exhaust for the block...

 

[stagrlee]

Then there's the 4L60 that will not be pleased about the added power, and the 8.6" rear may give up the ghost after a few good hard launches. You may need to beef the trans up, replace it with a 4L80 which has bad gear ratios for a screaming LS3, or maybe a 6L80 swap could be done if you're gonna run the 52x crank. That opens up another can of worms through, lol

Doing my fluid swaps before some January skiing. I'm with you, a 6.7L on a 5.3L setup is a concern for the tranny and diffs. The G80 gov-lock exploding pumpkin especially. Since hard launches tend to just wheel spin/slide the truck I just don't do it. I got other cars for that stuff

This is my G80 8.6" rear with 210K miles, about 40K with the 6.7L. About 10k miles pulling a 7,000 pound Airstream. Fluid swaps with foot control help!