I am putting a carbed 383 in my car and was wondering if their was anyway to keep the stock guages and if i could keep the stock fuel pump and regualted it down enough to use with a carb?
Thanks Matt

 

Only the tach and speedo are related to the PCM. Oil pressure, coolant temp, voltage and fuel level are independant systmes. Are you keeping the Opti/PCM for ignition timing, or are you going to a conventional distributor?

Without the Opti, you have issues with the stock PCM running the fuel pump. Without the stock PCM you will have a problem connecting the VSS to the speedometer. Nothing impossible... just takes a little work.

 

I Am goin to take the whole motor wirein harness and all out I am goin to a convential Dist. an A MSD box so you are basicly sayin all the guages will work but the speedo which Doesnt work now have a TH-350 an never hooked it up. So what can i do with the fuel pump if i am goin to remove the ECM competely

 

Depends how you want to operate the pump. If you keep the recirculated system, and simply attempt to drop the pressure to carb levels, you just need to wire the fuel pump relay to the ignition switch. My preference would be to use a dash mounted switch for the fuel pump, so you could arm it or kill it as necessary, interlocking it so it will only work when the ignition switch is in the "on" position.

I honestly don't know how happy the stock pump will be turned down to less than 10psi for a carb application. Its definitely going to flow a lot more at the lower pressure.

 

So the Gauges will still work then?

 

The fuel level is wired to the float sensor in the tank. The oil pressure sensor needs to be screwed into a port on your block, and is wired direct to the oil pressure gauge. The stock LT1 coolant temp gauge is driven off a sensor in the driver's side head. Not sure where the volt meter picks up system voltage, but its not from the PCM. Not sure if the stock LT1 tach will work directly off the coil on your new ignition setup, but I suspect it will.

 

Thanks for all the great Info. Anything else i would need to know for the swap would be great

 

the volts gauge will work and the fuel level gauge will work with no issues. As far as the stock pump, it'll work fine regulating it down. I used an aeromotive 5 port return style regulator before using a fuel cell and had no problems regulating down to 7lbs of fuel pressure. You just need to wire the fuel pump to a 12v source so it's on when the key is on. The fuel pump relay is in the driver's side kick panel. you can make it really simple by just making a jumper wire from the 12v wire to the wire to the pump. you shouldn't have any problems.