Has anyone done an L31 Vortec swap?

[GreaseDog]

I've got an 88 R30 cab I'm putting on my 80 K20 chassis. I've got the dual tanks, switch valve, lines, and the complete tbi harness to work with. I've also got a complete L31 Vortec and harness from a 97 Tahoe, a lowish mile L31 long block crate engine, a 4L80E, and a 90/91 VSS NP241 (set up for a driveline brake with a short shaft SYE conversion).

Has anyone done this type of conversion before? Ideally, it would be done to look almost factory. Any pointers? I could very easily go the 6.0/80e route, but the L31 is a known good runner, while the LQ4 I have on hand is unknown condition.

 

[bucket]

Holy crap! We ain't seen you around here in a coon's age! You even still have your original signature picture thing! Those are a relic of the internet past, lol.

How have things been?

 

[CalSgt]

Yup…
L31 & 4L60e in an ‘80 K-10, I did my best to keep it factory looking and mostly GM parts.

I’d say the biggest things to overcome were:

A reflash on the ‘98 PCM for my L31 was going to cost way more than just swapping to a newer PCM and re-pinning the entire wiring harness.

Updating the fuel system, but your ‘88 stuff will cover most of that. Probably just need to upgrade the pumps, add a filter and route the fuel line to the proper spot at the rear of the manifold.

I guess if you have the gauges from the ‘88 it should work fine with the VSS in your 241 case. I went to Dakota Digital gauges since my originals were worn out and the mechanical speedo wouldn’t work after converting my 208 case to use a VSS & reluctor.

Here’s my build thread
https://www.gmsquarebody.com/threads/80-k-10-squircle-build.34732/page-51#post-978595

You must be registered for see images attach

 

[GreaseDog]

Holy crap! We ain't seen you around here in a coon's age! You even still have your original signature picture thing! Those are a relic of the internet past, lol.

How have things been?

I've been lurking a bit here and there. Keeping up with things. Sripped the body off of my K20 in 2010, with the intention of a rebody. The donor body I bought ended up being further gone than I expected, and I mothballed it. Played around with some gmt400s for a while, and a dentside Ford (67k western 77 F350).

Stumbled upon a cab that was already redone, and I had a long history with. The truck belonged to my buddy Shorty, who YEARS ago hauled a Chrysler Newport to my neighbor's house to prepare for the local fair demo derby, which would start another lifelong affinity, going into my 26th season now. Additionally, it put my 74 Firebird away in storage in 2002 where it sat for 10 years, and another 13 in my garage before my buddy decided to give it to me. And hauled countless trucks and cars for me over the years. He sold it to fund a bigger truck, local body shop bought it for their shop truck and completely redid the cab. Shorty passed away while they had it.

When they upgraded to a bigger truck, another buddy bought it for his shop truck. He didn't realize what he was buying, as he was friends with Shorty as well. He discovered it was Shorty's truck when he found paperwork in the glove box. He used it and cared for it for several years, before the frame broke. He sold the bed off of the truck, and decided he was going to sell the front cab and clip I couldn't let it get away.

Collecting parts for various projects over the years, several of which stalled and moved on, I realized I have enough parts to actually put a truck together.


I had to reup the avatar, mine was gone. Lol

Oh, and I bought a gmt800 Quadrasteer too.

 

[GreaseDog]

I guess if you have the gauges from the ‘88 it should work fine with the VSS in your 241 case. I went to Dakota Digital gauges since my originals were worn out and the mechanical speedo wouldn’t work after converting my 208 case to use a VSS & reluctor.

Here’s my build thread
https://www.gmsquarebody.com/threads/80-k-10-squircle-build.34732/page-51#post-978595

You must be registered for see images attach

My 88 has a cable speedo.

I'll have to check the build thread later, that's exactly what I envisioned!