2003 Silverado RCSB Z71 6.0/ZL1 Blower & 4L80e/NP241 Swap
 

Hey guys, figured I would share some info and pics on my swap. Been running since early July and runs great.

Bought this truck in October 2016 from the original owner. Fairly well taken care of, but I knew a swap was in its future from the get.

Started with a long block LQ4 and 4L80e from a 2003 Burb. Ditched the stock heads in favor of a pair of LS3 heads with Howards springs. BTR pushrods, LS9 head gaskets, Chinese head studs, LS9 cam, LS7 lifters, etc Bought the blower assembly from another member and I had the CTS-V lid powdercoated semi flat black. Came with a 2.5" upper pulley. Running stock LS9 injectors. Aeromotive Boost Referenced FPR. Walbro 450 in the tank.

Speed Engineering 1 7/8" long tube stainless headers and true dual 3.0" stainless exhaust. Going with larger mufflers or one large dual in/out muffler to quiet it down. Guess I am getting old....lol.

Had the 4L80e rebuilt from my transmission guy, all the usual upgrades, and ordered a Circle D 11" converter for it. Stalls dead on 3k. Dextron VI fluid. Custom tubular crossmember. Went with a NP241 transfer case to rid myself of all the Autotrac shit. Had the NP241 resealed and filled with Autotrac II fluid.

Went to the larger 31" core radiator too, along with a GMT900 set of eFans.

Adding pics....

Pics....

Awesome! That's a hell of a sleeper!

Lookin' good, thats a sleeper indeed. :nod:

How much boost are you getting with that 2.5 upper?

Only 7.5 or so. Running a stock diameter crank pulley, so the blower isn't spinning much fast (if any) than a stock LSA/ZL1. Still putting down 525 to the wheels on any day above 100, if it's in the 70's it brings the IAT lower and I get a few more degrees of timing and then I get 550 to the wheels.

Cool build. Boost is lower than I would have guessed, but that seems to be the trend when an LSA is put on a truck with the factory balancer.

The LSA blowers benefit a ton from a port job. The rotor pack is kind of choked down without it.

When the time comes for more power, get yourself an OD balancer with 8 rib accessories, swap to a more aggressive and truck friendly cam, port that blower and let this bastard eat!

That's a nice blower you got there :nod: and some great power numbers too

Eventually I plan on building a forged short block from a 6.0 Gen IV block (with a 24 tooth reluctor wheel swap). At that time I will have the crank double keyed and run a larger diameter crank pulley. An 8 rib conversion will happen then too. I will also likely also buy another lower blower unit and have it rebuilt and CNC ported. I seriously doubt I will go with more cam due to the fact it's my daily driver and my tow rig. I got another LS powered toy for the big cam, boost, etc (see sig).

I'm just in the market to do this set up on my truck. But i need more feedback in to where I can order pulley accessories and all the small thing that need to be done

Not what I went with, but most use these guys.

LSSimpleLSA blower and fellow power adders & Fbody hot sides ? lssimple.netLSSimple email mrmurphy@msn.com with desired combonations