Sierraman02

Hi guys first post, I have a 02 sierra 1500 4x4 z71 with a 5.3 and have a entire 2002 sierra 2500HD 4x4 doner truck to take parts from. I want to build the lq4 engine it has already know what im gonna do on that end my question is what do I need to swap the 4l80e in I will take the 2500 wiring harness what do I need to take from that truck to do it thanks.

FFDP

iTrader: (2)

Well you'll need the engine/transmission/transfer case. Then measure and build two new driveshafts unless the front driveshaft from the 2500 truck will fit in the half ton front diff. Maybe a u-joint swap or something.

You'll have to mod your cross-member or buy one. Some guy on here sells them, I just forget his name.

I highly suggest you purchase larger fuel injectors if you are going to mod the engine. Both the 5.3 and 6.0 run the same exact injectors and they are barely big enough for a stock 6.0. You'll need a custom tune of course for all the swap stuff too. If you want your VIN to match you'll need to keep the 5.3 and flash it with a 6.0 file and 4L80e transmission segment. All that could be done with HP Tuners software.

Sierraman02

Thanks for the info I couldn't just take the 2500hd cross-member then does all that engine/tranny/transfer case drop in? Would it be worth to take the rear axle and front diff then to, if they would fit.

FFDP

iTrader: (2)

The 2500 frame is nothing like the 1500 frame. The cross member is not in the same place for the transmission. That why you have to chop it and move it/weld it to fit.

The front diff won't bolt in because the frames are not the same. Rear axle is not required. The 10 bolt is more than willing to accept a 6.0. Though upgrading the G80 or open diff to a real locker in a very good idea. Also the 10 bolt is way lighter and the 14 bolt is a better idea if you are making like 800hp or something.

Sierraman02

Alright so just get a cross member and the tranny and transfer case will drop on in then thanks for your help the engine will being making around 450-500 crank.