[RichardJ]

I bought my GMC in '85. I was freshly divorced and it was my only insured vehicle and daily driver. Driving a lot of miles, the points change or cleaning and dwell adjusting was occurring way too frequently for my liking.
I installed a junkyard HEI. It started twice. I set the timing and put my tools away. It didn't start a 3rd time. I had wired it as above with a new wire and bulkhead connector.

The module was fried. I removed the by-pass (yellow) wire from the solenoid. I reinstalled the ballast resistor and connected it directly to the HEI.

It has been running with the ballast resistor powering the HEI since about 1989.
That original HEI was the coil-in-cap style. When I installed the AC, I switched to the '75 only external coil HEI for compressor clearance.

The truck will run 70-75 all day without a whimper and if i keep it at 65 it will get 15 MPG. It starts immediately and doesn't care that kind of **** I put in the back.

I have a 2018 RAM SLT 3500, but most days I drive the '67 GMC.