Here is a quick question for you boys..

I am looking to put an RPM gauge into the ute, removing the clock but i want it to be accurate.

As from the tech wiki it states the A15 having - 67hp @ 5200 RPM

Now with my setup of:
Dual side draught webers 45mm
Genie extractors, 2.5 inch exhaust
CAMSHAFT 312-7.5
lightweight push rods
OVAL CYLINDER HEAD H75
Double valve springs
large 36mm valves
Roller rockers and collars

i am really unsure what the top RPM would be on the engine and what the hp reading is currently.. when would she redline?? is there a way i can work this out so when i put in a tacho it is accurate to the engine??

or is the best way to put it on a dyno and it will tell me??

My mildly worked A14 is doing just shy of 8k... if that's any indication

8500-9000k. That's what my old A15 did with a worked motor. I think your cam is the key. Hard to say what your hp will be. Maybe 110-120hp. You'll have to get it dyno'd.
Nice setup.