Are the both springs the same?
Factory distributors can work with two different springs and make a curve, but a lot of the aftermarket ones can not work well that way.
I'd first work on reducing the rpm drop going into gear.
Is it better than when you had it at 17* ?
Then I'd go with less initial tension on the weights. That might mean a pair of lighter springs - which also mean quicker advance. With no vacuum advance, that should not be a problem. If there is ping (detonation), note the rpm and whether its part or full throttle. I'll be surprised if its at part throttle. May have to limit the total with a bushing or by heating and bending. Crackedback sells bushings in sizes MSD does not.
Heating and bending MSD/Delco advance info here. (do not join tapatalk, just click past any pop up)
MSD-Delco Distributor Weight Modification For Less Advance