Swapping Gauge Cluster
 

I want to swap the gauge cluster in my 86 Z28 to a metric unit with 230km/h (145mph) speedo. Currently the car has an 85mph unit, and the tacho doesn't work. My car is a factory 5 speed, where the new cluster is probably from an auto.

Will there be any issues with swapping the clusters over? Will I need to get the speedo recalibrated?