The starter you have is a 4.4:1 gear reduction starter.
You might have been able to solve your starting problem by going to a 3.75"1 ratio starter. 25% more cranking speed.
https://www.summitracing.com/parts/p...1/make/pontiac
Have you put your car on a dyno to see what your HP gain might be after you went with injection and the latest ignition system ?