Wiring 50 Ignition Switch with Custom Harness & LS

[Curt - TN]

I am installing a speedway harness in my 1950 Truck and the 3 post non-acc ignition switch has me stumped.

I checked the ignition switch with a multi-meter and it appears when the key is turned on all 3 posts make connection.

I am assuming I should be able to use the factory style switch as long as I used an external starter button, correct?

Below is a picture of my wiring diagram and here is what I think will work. Put the tan 4B on one post, the red which is battery source on another post and the pink 3B which is labeled ignition on the 3rd post. lf I am correct that should work for ignition on and off.

Next I need to care for the purple which is the wire to trigger the starter. I assume I would take power from either the ignition or acc lead and run it to a separate button on the dash then run it to the starter trigger, this should stop the start form being triggered if the key is off.

Have any of you all done this in the past and does this sound correct?

I will have the computer and fan relay draw direct from the battery but the lights, gauges and A/C would go through the ignition switch so it should not be huge amperage. The switch is new.