1990 350 sport swap in 1994 sunurban 454 4l80e questions

[Mr.Chevy4x4]

Ok, let me start off by saying I have done searches and read a lot of threads looking for this info. I'm hoping someone has done something similar and can help with the specifics.

I have a 1990 sport 2wd pickup with factory 350 700r4 combo. I recently scored a 1994 2500 2wd suburban with a 454 and 4l80e trans. I have been toying with the idea of swapping the suburban drive train into the sport to make a pseudo 454ss.

I can handle all of the mechanical aspects with no problems. My concerns are with the electrical requirements. I would like to swap in the tach instrument cluster at the same time that I do the engine swap.

How much of the suburban harness do I need to swap into the pickup? How involved is swapping out the dash harness for the cluster swap? Any insight into what I am getting in to will be greatly appreciated.

If you have any links that can steer me in the right direction, that is appreciated as well. I don't mind reading to learn what I need to know.

Thanks in advance for your time!
Mike

 

[someotherguy]

Nice project; you'll want to bring pretty much everything over from the donor. Good news is it's not hard. Engine harness, dash harness, PCM, etc. You'll find a couple of small gotchas like the hole in the firewall where the engine harness passes through has a different shape block where it attaches at the firewall, and the 1990 dash shell is a little different where the harness connector for the cluster sits; it's completely recessed whereas the 1992-up has a small standoff for the connector - those that have done just the cluster swap alone seem to make do without a lot of hassle though.

If the Suburban dash shell is better just swap it whole. While you have the dash pulled, give the HVAC ductwork box a good looking over; the pre-1994 unit has a 3 speed fan setup; with a little work you can move the 1994 4-speed resistor, relay network, etc. over so the dash harness is a direct fit.

Richard