Gauge Cluster Woes (More Pics Added)

[Mr. Lee K30]

So a few days ago I scored a Tach Cluster to replace the standard cluster in my '77 Crew Cab 4x4.  The Tach cluster had the mechanical oil pressure gauge and Volt gauge that my current cluster has and was told it came out of a Suburban. 

I compared both clusters side by side and found some differences that makes me wonder whether or not this is gonna work...

Tach Cluster






My Cluster






The Tach cluster doesn't have the 4-WHEEL LOCK light which I would like to retain so I figured that I'll just swap Speedos... but if I did that I won't have the BRAKE warning light.  Could I just swap warning lights with the Suburban speedo and tach so I can use my original Speedo?  Any other thoughts, experiences or insight would also be appreciated 

[ccz145a]

Looks like all you'll have to do is cut yourself a hole for the 4-Wheel Lock light and use your old speedo with the new housing. All the circuits for those lights seem to be in the same place.

Now for the fuel guage, you are going to have to change pin location for the fuel guage wires in the connector. Need some pics of the other half to help out.

*edit
Well looked at it some more... You will have to re-pin the brake light to turn your old oil light into a brake light and build a partition into the light housing behind the speedometer, ought to work.

[Mr. Lee K30]

Here's some pics of the harness connectors:




The left connector is from my truck and to the right of it came with the Sub tach cluster

[Mr. Lee K30]

Now for the fuel guage, you are going to have to change pin location for the fuel guage wires in the connector. Need some pics of the other half to help out.

Pics were added on the original post

[ccz145a]

Have you tried to get one of the pins out of the connector? I have never done it, but am thinking it wont be too hard.

I know the top pin closest to the speedometer on your connector will have to be moved to the third one up on the other side.

I don't have time right now to figure it all out, but give a try yourself. Trace the circuits and see what goes where. I will have more time this weekend.

Good luck.

[Prong]

I'm 99% sure the tach cluster is from a 76. If you're handy with a dremel, you could fabricate what you need. Good luck and keep us updated.