Vortec 4.3 to 5.7 swap questions

[98chevy2500SS]

Short story: recently got a 1997 Chevy C1500 with a blown 4.3 and my dad and I are going to be swapping it over to a 5.7.

Upon my research, I'm going to need to find a computer from a 1997 truck with a 5.7 in it, does it need to be from a 2wd or can it be from a 4x4? Is the firewall-to-engine harness different or are they the same? I am going to have Black Bear tune it at some point (long tubes, gear swap, EGR delete, tire change... all that fun stuff), so will it matter in the end which one I grab?

 

[98chevy2500SS]

Bump, anyone know this?

 

[stutaeng]

It's pretty easy actually from when I was looking at swapping my 4.3 Vortec. You can just add the 2 additional injectors to your harness.

Reflash your existing ECM for the V8.

There's a really good how-to thread on one of the S10 forums...let me find it.

 

[stutaeng]

I came across this from the LT1 swap website: http://lt1swap.com/v6_to_v8_vortec_conversion.htm

I also think the knock sensors are in different locations. My V6 had it on the rear by the bellhousing. The V8 i think has it below the engine. Those are easy wires to reroute though.

 

[98chevy2500SS]

Good read, thanks for the link. I'll try and see what I can do after we get done with the harvest.