Still trying to map out a timing curve

I thought 3000 was good, but looking at original MSD distributor curves, it depends on your springs. I had two silver springs, but have no way of knowing if they were heavy or light. Stock MSD Pro Billet dizzy with heavy silver springs is all in at about 5300. Two light silvers it's all in at around 2400. I'm hoping for great advice, but otherwise will play with all different curves.