80's half-moon gauges to 90's needle

[Willie_Rae]

I'm looking to swap my extremely hard to see 80's-era GM half-moon gauges to the 90's needle gauges because I read that they will swap over with just a little wiring work.

I'd rather have the late 90's with the 6k redline but I read they were harder to wire up? Pictures will go a long way, much appreciation for any help provided!

Motor is a 350TBI (soon to be carbureted because TBI is completely shot) with sm465 trans in a 88 K2500 reg cab long bed

 

[magimerlin]

Look/search in the tech section. There is a couple write ups on how it's done. And has pinouts for the wiring in one of the posts too if I remember right.

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

[DerekTheGreat]

What magi said.
I've done that mod to two trucks now and you'll want the unicorn 91 or 90.5 instrument cluster. It is configured for the same harness as the early GMT400's but you'll need to move some wires over. It's a great idea to just keep searching scrap yards for one and when you find one, take note of v6 or v8, tire size & rear gear ratio. That write up has a break down to help decide what you need to do in order to get the speedo right. In both cases I got lucky and the cluster was already wired the way I needed it to be. Expect that the tach doesn't work or is Wonky. There is a company here in Michigan, SpecMO, that can rebuild your cluster with fresh orange needles and a new clear lense if need be.