Lsierra32703

Ok im here to bust a few myths on this swap... the 4.3 and the 5.3 share the exact same motor mounts, the inside wirering harness for the v6 has to be completely removed and swapped for the new body control module to work so you have to use the o4 inside harness and body control module the v6 pcm and body control module will not work for this new of a motor even if reflashed harness plugs are completely different and can not be repinned to match unless you are just that awesome its to much hassle for little accomplishment the fuel lines have to be changed from the fire wall up and the gear selector module on the transmission has to be changed to the one from the 04 its a simple part swap and you can simply plug n play for lack of a better term... half of you are thinking bullshit but im doing the swap right now and have pulled both motors and have talked to some of the smartest and most experienced mechanics who will all approve this because its right...more info on the swap as it continues

ls1nova71

iTrader: (4)

Maybe it's just me, but I think this might be more pertinent information if we knew what kind of vehicle you're referring to....

Lsierra32703

Silverados/sierras sorry thought i added it in the title

tfi racing

iTrader: (2)

Tell me more about those magic motor mounts,my 2000 2wd Sierra definitely needed the 5.3 engine mounts and frame brackets. Also tell us why you had to rewire the entire truck,way simpler to get a 2000 5.3 engine harness and just plug it in.

Lsierra32703

Idk why you had to change your mounts my 5.3 bolted right up same 3 bolt mount and im switching to drive by wire from drive by cable.....