Re: Timing and carb choice
Welcome to FF gunna.
7* timing is nothing huge - but there should be NO pinging - not even a little. This can damage your motor.
Your high altitude 2300 feet would cause a normal car tuned at sea level to run rich. ie: less air, same amount of fuel. This would reduce pinging, as its the lean (low fuel) case that would tend to ping more. You can get your car tuned using an airfuel ratio meter so the jetting is spot on for your conditions. Drop it back about 2* from where the pinging starts.
Try 98 octane premium BP Ultimate, Mobil Synergy etc (not the 96 stuff). Your 351 doesn't have high comp 302 heads on by any chance?
Another thing to consider is your TOTAL timing. You have 7* static timing, but the dissy has a certain amount that comes in automatically as the rpm increases (eg 35*), which would give a total of 32*. This will all be in at ~3000rpm. Mark your balancer and check the timing whilst revving the motor up.
The only gas I like is gasoline. Not sure on prices. Others can help out here.
MSD Blaster 2 coils aren't too bad.
393 Tremec TKO 9"