I am swapping my whole cracked dash out for a new one, removing the rest of my heater/ a/c stuff and dumping a bunch of wires and excess stuff out of that area when I cant get the speedo out. Long story short i broke it its unusable I want a 145mph cluster now(forged 383 will def need more than a 85).

My questions is regarding the rpm gauge. My current cluster doesnt have one, the 145 one does. My car has no ecm its a sbc as little wiring as possible. How or what do I have to do to get the rpm gauge to work correctly? Or should I just swap the 145 mph gauge in place of my broken 85 mph gauge in my current cluster and be done with it?

 

You don't need the ECM. Check the following link for more info:

https://www.thirdgen.org/gauges

JamesC

 

Thanks for the quick response.
Iv read that before and it describes wires coming from coilpacks to the gauge. I have a distributor on my car most of the stock wiring to the engine have been cut out btw. In this case what would I need to do to get the rpm's working? Im guessing wire up a wire from the tach side of the distributor to what on the cluster?

 

Anybody?

 

Thanks for the help guys

 

My guess would be to take the tach out of the cluster and look which contacts match with the plugs on the back of the cluster. Then wire in a small length of wire from that at hook it to the hei prong. I know that the stock wire for the tach is brown, so you might have that to work with. most gm cars had the wiring for the tach, only bundled up and not used.

Cheers!!!

 

Thats the kind of anwser I was looking for thanks. Any one know which wire on the harnes is for the rpm gauge? Ill take a look tonight my self tho.

 

My 85 - 145 swap was really straighforward. Since the gearing didn't change, didn't have to worry about it. Both units from an 87 IROC donor car.