i am going from a 91 3.1 v6 to an 86 5.0 quadrajet and i have the computer to the engine but not the wiring harness but i see that some people said the harness is not necessary and that i only need about 10 wires to run the engine. i really need the engine running and my car drivable again but i either have to go get the harness and use the computer or wire it myself, i have a/c how will that work if i wire it myself? the harness is $90 and this is definately a budget swap cause i am broke lol please respond quick
and someone mentioned use my old harness but there is a ton more connectors on my 91 harness than there is on my 86 engine (i dont know what to do)
thanks in advance

 

I've got an 87 ENGINE only harness for $75. No Need to ship cause I'm in Rhode Island too. This is NOT an ECM harness,.... just the wiring that the V8 small block engine needs in order to run. ( Starter, Alternator, Distributor, Gauges, ect.. )

You will have to overcome a few changes to your current set-up in order for a older small block to run properly in your 91. Most changes can only be covered in detail once you know how you intend on procceding with the swap.

You might need to bypass or delete the VATS security system.

You'll need to either drop that tank and remove the 3.1 fuel pump,.... or get a fuel pressure regulator so the fuel pressure is about 7-8 lbs or a carb will just keep flooding out.

You might need to change a couple plugs or a couple sensors so the older harness can connect to the sensors and engine accessories correctly.

You'll need to decide on a engine fan,..... either run a clutch fan or figure out how to wire the existing electric fan back up.

To get the AC working you'll need to use AC parts that will fit properly on the V8 engine. It will work fine if everything is installed right and it gets wired the right way. ( AC is a pretty low priority at this point. )

You might need to figure out the speedo wiring too so that it still works when the ECM is removed.

There's probably other stuff I'm forgetting, but you can see it is going to take some time - money - and effort to make the swap a success.

 

It is a carb engine is that what your harness is to? I need it so if it will work (I will pm you my phone number that would be easier