I think I may have it, Your idle is 800 and the double MP light springs start advancing at ~600 so I think you're already into the slots at idle & if this is correct no wonder only 5 deg of mech was left. How about trying this, use the orig OE light spring plus the orig OE light spring from the dist you found (2 OE light springs) plus keep your current plate. this'll start at ~900 which is above your 800 idle. set the initial back to where it was, 18 right? then run it up & see what your total is (vac adv plugged as always) and at what RPM (for reference) it maxes out at