I have done some searches and still cannot figure this timing deal out with msd's charts. I have the msd pro billet distributor in a 499" RB. I am trying to go with 38 degrees total all in by 2500-3000 and lowest possible initial timing so it will start. Which spring and bushing combination will achieve this?

i had a 493rb with the same dist. i just locked it out, 37 total, street- strip. never had any problems starting. no detonation. 13mpg staying out of it. stay safe, seeya.

Two sliver light weight springs all in by 2500-3000. The bushing depends on how much intial you want. So set it to 20 intial and put in the black bushing gives you total 38.
Red 28
Sliver 25
blue 21
Black 18