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

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