4L60E to 4L80E swap.  Discussion in 'GM Powertrain' started by
Sierraowner5.3, Jan 3, 2012.    1. Sierraowner5.3
Sierraowner5.3 Rockstar 4 Years 1000 Posts      buddy of mine
has a 99 stepside reg cab with a 5.3, 4x4, 183,xxx mileage. his
tranny is going, and he is wondering how hard the swap would be,
he knows its not a bolt and go, but besides the computer and the
crossmember, would it be terribly difficult?      he also knows
that he would need another 4x4 one.      hes a mechanic for the
army, so hes fairly savvy on mechanical stuff.    2. murdog94
murdog94 Epic Member 5+ Years 5000 Posts      I believe the
transfer cases are different as well. but the 4L80 should be the
same lenght, and bolt in the same, as well as the computer
inputs so really he would just need to measure one, and check on
the transfer case mounts (number of bolts and spacing) so really
if that is the same (im not familiar with the 4L60 auto transfer
and the 4L80auto transfer if that is what he has) but the tranny
cases as fa