First, I found my mystery wire is for temp sender. There is a 1/8th sender unit with single spade on the thermostat housing itself (pegs needle) and one just below it and closer to the carb on the intake manifold. Which one is it supposed to go to and are there usually two?
Now the biggee. Rebuilt the engine: honed cylinders, new bearings, reused oil pump and cam timing chain (less than 5K on them both), installed balance shaft eliminator, new rings, new rebuilt head as the original cracked and was reason for rebuild). Adjusted the jet valves cold.
Engine fired fine but now it ticks. It sounds as if it's coming from the front cover? I'm going to pull the valve cover with the truck "nose end down" and run it for a short time to see if I can pinpoint the noise. I understand a lifter tick, or a jet valve out of adjustment tick, but would could tick under the front cover?