4L80E w/ Manual Speedo

[JCampbell]

Ouch. I just priced manual speedometer tail housings for the 4L80E. At over $500 bucks, I’m looking at other options.

Does anyone know if the ’91 trucks had electronic speedos? It sure seems like it would be much less hassle and a whole lot cheaper to swap in an electronic gauge cluster than to swap tail housings.

Anybody else run into this issue? What was your solution?

[Jonboy]

It is most 90 4wd and all 91's that had the electric speedo. If you are doing an LS swap (or LT1, for that matter), the PCM has the buffer built in, and is a single wire hookup.

[JCampbell]

It's a TBI conversion.

[Jonboy]

That may depend on the year of the ECM/PCM that you are using. The 90-91 trucks used a DRAC as a buffer for the signal. It is located under the radio. You may need that. I think if you are using a PCM, it may have the VSS out already in it (and then should be the 1 wire hookup).

[JCampbell]

It's a 454/4L80E out of a '93 C-3500. From what I understand, that year uses the VSSB unit.

I did a little more research and I found a unit that converts the pulses from an electronic vehicle speed signal (VSS) into cable drive. For a "buy it now" price of $280, I'm thinking this is the way to go.

http://www.abbott-tach.com/cablex.htm

http://www.ebay.com/itm/Cable-X-3012...item4cfec995b1

[ghettoluxury]

You can use a 90/91 cluster with your 93 tranny.

[JCampbell]

Good to know. Thanks.