Mopar Electronic Pickup Polarity and Rotor Phase

Mattax said
I wouldn't switch the leads at the same time you are reworking the curve unless you know its backwords.

Yes, switch to manifold source if the current setup is causing the coolant temps to rise and not stabilize at idle. Not toalking about the usually rise that accompanies the reduction in airflow when coming to a stop.

I agree.

Fuel mixtures and timing work together. Can only do so much with the fuel mix if the timing isn't where it ought to be.

Well there's part of your answer! And unlike your car, 70 mph probbaly hurts milage vs. 60 mph.
Also any time spent idling, tuning, etc is a gas milage killer. The mpg of both my vehicles plummets when driving in the city. Literally more time spent idling than moving.
All these things add up.

Well I don't really know a way to tell for sure if they're backwards but based on the fact that it runs better now with the ign box set to rising edge and that I had to change the phasing of the reluctor wheel (swap roll pin location) when I first got the distributor so it wouldn't misfire like crazy leads me to believe that's the case. I'll try swapping the pickup leads first, check how it runs then go from there.

I know for sure there's a lot more wind resistance above 60 mph, the truck is shaped like a brick with big flat frontal area and fairly high ground clearance. It cruises really nice at 70-80 mph with the 2wd fully independent front suspension and has plenty of power, I just need more self-discipline to keep cruising speeds lower.