Cristiaan559

Hello, i have a 2003 Chevy silverado 5.3 4l60e 4x4 that the motor seized up and bought a donor 99 2500 6.0 with the 4l80e 4x4 truck to swap motor and tranny over, my question is
Would it be direct swap in place for my original tranny and motor or would i need anything else off the 2500? I have every part from 2500 truck to swap over, just want to know if i would need to buy anything else. Also i heard the 99-2000 lq4s are different then the newer lq4s? Thanks in advance for info !

FFDP

iTrader: (2)

The 1999's are drive by cable and you can't use that. So you have to swap your top end over to make it function.

That means intake manifold/throttle body, fuel injectors, fuel rail, EVAP stuff. Possible that the PCV system is different so it may need the drivers side valve cover swapped as well. Your 2003 truck does not have EGR and that 6.0 does, so you need to swap over your current passenger side exhaust manifold.

The early LQ4's have iron cylinder heads that are worse than the later 2000.5+ aluminum cylinder heads and I think the early engines also had paper head gaskets instead of MLS gaskets. But maybe someone has already been in that engine before.

You will have to modify the transmission crossmember to fit the 4L80 because the mount location is different. Likely you'll need to get your drive shafts modified as well.

Past that it will require a tune to make it run and drive.

Cristiaan559

Alright thanks for the info, about the cross member and drive shaft can’t i just use the cross member & drive shaft off the 2500?

shakenfake

No because the tail shaft of the 4L80 sits farther back than the 4L60 so you need to extend it on your stock one since the mount points are different. Also I think that the 2500 crossmember is too big for the stock location anyways.