Official NBS 4.3v6 to GEN 3 V8 swap Guide

[BIG BLOCK 555]

i have sierra 2001 v6 4x2 AT ( 4l60e ) i want to swap to an LS1

this is my first GM car ( Japan user ) i live in saudi arabia i asked everbody about this swap no one have a clue about it

so here is My questions :

1- i did find an engine without harness & PCM
2- i find an engine harness from a 2001 sierra v8
3- also find an engine mount & frame mount
4- i find a flex plate & torque converter from a v8

q1 - do i have to change any interior harness ?
q2 - do i have to send my pcm over to allen or any tuner will help ?
q3- i have been told that the gearbox housing is not the same as a v8 ?
q4- do i have to change fuse box or just leave it as it is ?


i have been searching all over i didn't write this until i am 100% sure that i didn't find any answer to my questions

thanks to OP for his work and effort & everybody have been helping

[blacstar]

i have sierra 2001 v6 4x2 AT ( 4l60e ) i want to swap to an LS1

this is my first GM car ( Japan user ) i live in saudi arabia i asked everbody about this swap no one have a clue about it

so here is My questions :

1- i did find an engine without harness & PCM
2- i find an engine harness from a 2001 sierra v8
3- also find an engine mount & frame mount
4- i find a flex plate & torque converter from a v8
looks like you have everything
q1 - do i have to change any interior harness ? nope
q2 - do i have to send my pcm over to allen or any tuner will help ? send it to allen
q3- i have been told that the gearbox housing is not the same as a v8 ? transmission is the same
q4- do i have to change fuse box or just leave it as it is ? leave it


i have been searching all over i didn't write this until i am 100% sure that i didn't find any answer to my questions

thanks to OP for his work and effort & everybody have been helping

start wrenching

[BIG BLOCK 555]

thanks a lot blacstar

i will do the swap by my self .. is it ok to go with v8 PCM ?

[zebra]

it's newer than 99, so it already has the V8 PCM - so long as it's the silver one.

[BIG BLOCK 555]

i faced some problems during my swap any help will be good

1- the frame mount don't fit under oil pan but my stock one fit great .
2- there's some holes under water pump what are they for ?

[blacstar]

i faced some problems during my swap any help will be good

1- the frame mount don't fit under oil pan but my stock one fit great . V8 frame mounts and V8 engine mounts- they will fit
2- there's some holes under water pump what are they for ?

do you mean open threads? any pics

[BIG BLOCK 555]

i guess it's .. i will upload some for you

i install my engine without looking on this :l ,

also about my engine harness ( new one ) do you guys have detailed pic's installation ?