I want to add a factory tach to my 1990 Jimmy?

[1990Jimmy]

What all do I need to buy? My 1990 Jimmy is stock with a 350 TBI with HEI. What gauges (part numbers please) do I need to buy?

 

[nvrenuf]

At one time, LMC offered a tach conversion kit but I think they've been out of stock for a while.

That said, yours may be more tricky than usual because 90 and 91 squares have an electric speedo which can not only make things a little more complicated but also changes the shape of the gauge housing that holds everything.

 

[gmbellew]

agree with above, based on my research on my 1990 burb. I think Dakota Digital is the answer for 90-91 if you want something that looks stock. otherwise add a tach at some other location that suits you.

I just use ALDLRdroid app on my phone and a OBD1 Bluetooth ALDL reader to check engine RPM if I need to for any reason. not as convenient as seeing RPM all the time, but certainly is cost effective.

 

[ChuckN]

I did mine from LMC @1990Jimmy - it came with the rear backing plate for an electric speedometer, but mine used a cable.

Long story short, if you go this route and decide you want my backing plate for the electronic speedo, you can have it. After that, I believe you would need a small fuel gauge for the side cluster, the tach itself and the little pigtail that goes with it, and the printed circuit for the back. The kit came with the little metal clips that go in the backing plate that the gauge studs push through to make contact with the printed circuit (and also hold the circuit in place) but it’s possible that you could reuse them.

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[Bennyt]

The LMC kit is pretty nice and complete. I purchased it for my son's '77. I paid $285 for it last year with a LMC coupon I got. I did have to wait 4-6 mos as it was on B/O.

I have a '90 CC that I plan to buy the same kit for, The odd thing is my '90 has a factory mechanical speedo, maybe because they were T400's?

 

[nvrenuf]

@Bennyt everything I’ve ever seen/read indicates the 90-91 all had electric speedos regardless of transmission. Maybe yours has a very early production date?