Swaping gauges

I have been looking into changing my gauges. I have found a set that I want. Just need to know if the speedo will work?
www.dimecitycycles.com/vintage-cafe-race...edometer-490291.html

It says "The speedometer ratio is 60MPH @ 2400RPM"
I have found a few others saying 60mph@2240rpm.
I really want the white one in the link.

And am I correct in thinking the 1:5 ratio on a tach will work? Dime city cycles shows it will on older kawi's.
www.dimecitycycles.com/vintage-cafe-race...hometer-15-0080.html

The ratio is 1.5 to 1 on all the KZ650..KZ750...KZ900...z1...z2....AND KZ1000 MECHANICAL GAUGES UP TO 1980.
Any one of those will work....except the 74 and 75 Z1B tach which has a brake light in the faceplate.