[Marty Phipps]

I just went through the same dilema with my 428.
Backed off timing, no difference.
I actually ruined 3 starters before I was finally able to get over this.
Broke 1 snout, disentigrated one starter gear, fried 1 motor.
I finally had to go to a 700 cca battery, and a heavy duty starter.
I went to Schucks and ordered a starter for a 72 455.
The motor is still a little slow to turn over at warn up, but it'll start.
Another thing I've started to do, is open the hood while the car is parked.
That allows some of the engine heat to escape before restarting.