GSX tach differences

It's my understanding that 70 differs from 71/72.??

If so what's the difference? Here's what I have

 

That's an early tach. on the later ones, the hash marks were all white. This is a '72 tach.

 

Awesome, I got what I need then thanks

 

I assume the needle is Orange on the 70's instead of white?

 

I thought that the original hood tachs only had one illumination bulb?
I could of sworn that my original had only one bulb...huuummmm?

Eric / Oregon

 

My 1970 GSX original hood tach has two bulbs if that helps.
Jim

 

Original and repro both have 2 bulbs

 

71-72 I believe had a nipple for an air hose that 70 did not

 

That's rite I forgot about that , to keep it from frogging up

 

This is an original 72 GS/GSX tach.

 

The one in the original picture is a 71 tach. It has the 70-71 face plate but also has the nipple in the bottom for the hose.
Duane

 

For those that have the book, Tachs are on pages 35 & 70.