I have an 86 2.8 efi firebird with a 700r4.

I bought a carb 350 2 bolt main, and I bought another 700r4 from a v8 donor. Both 350 and 700r4 are mounted/bolted.

I was wondering what exactly i need to do now to get start the car and get the basic functions working.

Would I need to get a engine harness from a v8 car?

would i need to replace my v6 ecm?

Would my v6 interior harness work with the engine harness out of a carb v8 donor?

 

Hook everything up... the battery to the battery cables, alternator to its wiring, temp gauge wire to temp gauge sending unit, etc.

Not really. A few of the wires might not be long enough to get where they need to go, and need to be lengthened, and stuff like that; but ultimately a 6-cyl has all the same electrical parts that a V8 does.

Not if your 350 carb isn't computer-controlled.

More or less, yes.

Main issues you'll run across involve: the tach; the 6-cyl one is expecting 3 pulses per engine rev, whereas a V8 produces 4, so it'll read 33% higher than it did before. Which, like pretty much everybody else's, probably already read high anyway. And, the oil pressure sending unit for a V8 is designed for a max of 60 psi, but the 6-cyl SU is set up for 80 psi max; so that will read high. (think of the "actual" oil psi, let's say it happens to be 40 at the moment, then the V8 sending unit should make a V8 gauge read 67% of full scale; but the V8 SU will make the 6-cyl gauge also read 67% of FS so the gauge will say 53.3 psi when it's actually 40) And, without the computer, the transmission will have no lockup converter function, without some additional parts & wiring.

To minimize clutter, peel back the entire ECM harness - the big fat one coming out of the right fender well by the blower motor - roll it up and tuck it away somewhere out of the way, like in the pass side inner fender liner. All the wires you need come from the connector below the brake booster. Assuming again, that your 350 carb is not a computer-controlled one.

 

So all i have to do is rip out the ecm harness?

In terms of the interior harness, will the v6 fuse box work?

 

Your question was already answered above.

You may want to read the V-6 to V8 swap Sticky in the Engine Swap sub-forum...

 

Oh didnt realize, im new to all this so im familiarizing myself with all the wiring terms