Mopar Electronic Pickup Polarity and Rotor Phase

The Summit Billet distributor uses the same trigger setup as factory Mopar electronic distributors; it looks exactly the same under the cap. Where it differs is in the mechanical advance, it uses weights and springs supposedly adapted from the old Mallory units; much easier to adjust than the Chrysler stuff although according to @Mattax doesn't provide as linear/consistent advance with RPM. From what I've seen online it's also the same as the Firecore distributors.

I drove the truck to work today and it seems better but still not as good as it should be. Idk if I'm expecting too much but I feel like at idle with a stock cam it should be smooth enough to 'balance a quarter on the air cleaner'. I also filled it up with gas and this past tank only got 8.5 MPG, the horrible gas mileage is another reason I've been making myself crazy trying to get the tune just right. I've already gone through the carb and know that's good (tuned Edelbrock AVS2). I suppose at some point I'll try switching the pickup wires around and go from there. I do know I need to slow down the mech advance, it's all in by about 2000-2200 RPM which is way too quick, should be more like 3000-3200 RPM.
8.5 mpg is horrid, but insure you are measuring it accurately. Use gas station fuel pump readings (fill-up to fill-up) and mileage markers (or GPS), not the tics on the dash fuel gage and odometer. I carefully recorded mileage in my 1969 Dart w/ slant-six in the 1980-90's and consistently got 22 mpg highway, back when the national speed limit was 55 mph and before 10% ethanol. At 75 mph, expect 30% poorer. If truly that bad, it may be running rich to put raw gas on the cylinder walls, which is why engines used to wear out faster in the day.