I'll add another thing from my original conversion over 30 years ago. There is one thing that will be challenging & that will be to get the oil gauge, choke & choke like to all done up to be like a factory install. Your current configuration is having the tan circuit 31 oil pressure wire in the right spot in the connector going to the pressure switch plug which also has the brown/white stripe circuit 250 choke power wire & light blue circuit 78 choke feed wire. If you don't plan on having an electric choke all is good except the three wire plug but I'll be bypassing this set up. Now keeping the electric choke will require some stuff to be done. The factory set up is the tan 31 being where yours is with it going to the single wire plug for the sender. With the electric choke you'll still have the three wire plug but the tan 31 is replaced with a dark green/white stripe circuit 931 choke/oil pressure light wire which goes to the cluster connector in the middle empty cavity on your current set. For this reason you need to get the connector with a fair bit of wire on it to splice into & have the terminal end to plug into the connector. Also shows where that & the tach's white circuit 121 wire goes. Simple part (which I personally don't like doing) is cut the tan wire on the three wire oil switch plug & splice in either salvaged single wire plug with enough wire to reach the switch or use a female spade terminal with enough wire to reach. The at the plug with enough of the tan wire left (atleast 3 inches) splice a dark greeb wire (with or with a white stripe) with enough lenth to make its way into the car to the connector. This is where the donor connector's wire comes into play. Splice it to that dark green wire & slip the completed wire into the connector. Another way would be not cutting the three wire plug & just relocate the tan wire to the middle cavity & just do the work with the new sender wire being spliced to a donor wire with terminal end & put it in the cavity you pulled the tan wire out of. You can reuse the original oil pressure two blade switch with the conversion. I have on my current redo replaced the entire original harness with one out of a gauge car & redone all the needed added wires to like it was a factory job on the dash harness but I've became OCD on my wire work.
BTW to all, the super smart guys who did most of GM manuals used "gage" in most & slipped in "gauge" every so often. Just because you're smart doesn't mean you're smart.
BTW to all, the super smart guys who did most of GM manuals used "gage" in most & slipped in "gauge" every so often. Just because you're smart doesn't mean you're smart.
