Wiring a Tach... How do I hook it up?

[arthur6]

Guys, How do I hook up a Tach (03 Softtail Satndard)
I'm looking at a used tach (Drag Specialties- H-D - whatever)
I see some that were on a 95 FX, 98 XL, 02 FL - whatever...
I'm assuming these can be hooked up to my 03 FXST??
I'm looking at putting it on the handlebar clamp.
I have several tachs and clamps I'm watching online.
Saw one on a bike (was an H-D brand tach (2 1/4??) with a billitt looking clamp on the bar clamp, looked clean and nice) Cost at H-D is $300+, don't think I need to spend that much.
Just need to know if I can hook one up to my bike. I can work the mounting out pretty easy.
Thanks