hey guys got a complete 350 from a 88 gmc 1500 to go in my 87 iroc z
and need to know if the wiring harness for the injectors and sensors is all i need or do i need everything wire wise and will all the other wires hook up to the ecm from the 1500 no problems?

 

Does the Iroc still have the TPI on it? I wouldn't change the injection system to the truck TBI.

 

its still carburated

 

If your wanting the fuel injection you'll have to have the complete harness and ECM. You'll also have to have an electric fuel pump for the correct psi for the TBI.

 

For the fuel pump that's a different harness from what I can see right?

 

I'm actually not sure about that. Idk if it would be easier for you to use the truck harness or find a TBI car harness for all that.

 

They look the same to me. But idk if I only need the engine wiring harness or everything going to the ECM

 

In that case it is no different than doing a standalone EFI conversion.
You will need EVERYTHING from the truck setup to run the engine and the starter / coil / gauges ( + prob fan ) wiring from your car
you will have to supply power to the truck ECM

 

 

Just change the block out and use a 350 chip. You also need the correct 350 knock sensor and ESC module, and injectors,but custom tune can correct for your injectors.

 

I'd put the carb system on the 350. Easier, cheaper, will run better (assuming the exhaust is upgraded, anyway).

 

Yeah the I had full exhaust work done. got the engine out and broken down. for the gauges though does anyone know if the wires will plug straight in or will need adapting

 

Which system have you decided to use?

If you put the 305 sending units on the 350, you won't have any problems.

 

tbi. I kinda just figured the gauges would plug into the 350 ecm no problem

 

I don't understand why you'd go through all the pain of swapping over the TBI system when your carb system would bolt right on to the 350, but, hey, it's your car, your time, your pain.

The only gauges we're talking about are the tach (no changes to wiring), coolant temp (3rd gen sender will fit in the 350), oil pressure (not sure if the sender changed between TBI and an '87 carb system), and speedometer.

Speedometer might be an issue. I don't have a clue what an '88 Silverado used for VSS. '87 IROC should be behind the speedometer, with a cable-driven speedometer. If the '88 Silverado was a cable driven speedometer, you might be okay. But, TBI 3rd gens used a VSS buffer, and I'll admit I don't know details about that. My guess would be the '88 Silverado TBI also used the buffer. '87 3rd gen carb don't think it did (might have, or it might be compatible with the '88 TBI ECM as-is).

If this was my car and my project, not a doubt in my mind I'd put the '87 carb system on the 350. It'll bolt right on (just use the knock sensor and module from the 350). But, it's your car, your project, your time, your pain, so do as you wish.

 

thanks five7kid saved me a bunch of time on pulling wire from my donor.

 

I had swapped the tail housing to go from electrical to cable driven speedometer