I have a 87 Z28 with 85 mph Cluster, can I swap it out with a 140 mph one. speedo is bouncing around all over, cable is good and gear in tail piece is fine

Welcome to TGO. A search is always good advice on the boards, as some questions have been asked many times.

I'd suggest that you swap in the 145 speedo head instead of the entire cluster to avoid any possible electrical gremlins. The swap is direct. Since the odometer has probably taken a dump, the following link provides a fix:

https://www.thirdgen.org/forums/faq-...-fix-pics.html

It's possible that you speedo has gone south, but you might take a look at possible problems:

https://www.thirdgen.org/forums/inte...eedo-woes.html

JamesC

Thanks James
As soon as I find the 145 I'll pull it out and let you know how I made out
Ed

Thanks James
As soon as I find a 145 one I'll Pull it and let you know how I made out.
Ed