Hey guys, I am in need of some help. I have been in the process of swapping a 95LT1 into my 85 IROC. I am coming down to the little things and they are driving me nuts. (especially only being able to work on it during the weekend). I have the engine all in the car, and it runs. Thanks for the tech info on the forum, no way I would have been able to do it otherwise! My dilemma is the speedo and dash wiring. From what I have searched people have swapped in a later style cluster with an electric speedo, but I have also read that they are not interchangeable. What has everyone done? (aside from getting a converter box)

 

To change to a later cluster, you'll need to also swap out the dash harness that has all the provisions for the electric speedo.

Other than that....a CableX box is what you'll need, or putting an Auto Meter electric speedo in the place of the stock one.

 

I think for that year you just have a cable driven speedo. So you should just be able to reconenct the cable, unless you changed transmission.