The timing ramp (or curve) will be different from engine to engine. There are many factors that need to be taken into consideration. I actually set mine by trial and error. After reading various articles and posts on the subject, I figured I needed about 36-38° total advance. I also read that it should be 'all-in' by ~ 3000 rpm. After some experimenting with the different ramps, I ended up using ramp "C" on the MSD instructions. My initial is now at 16°, total at 37° and using a 21° bushing. This seemed to give the best performance throughout the rpm range with no pinging that I could detect. Remember, your's will be different (I'm running a 390 FE).
If you want to get real technical, here's a quote taken from an article I read a while ago.
"Optimally, the timing curve should be set so most of the fuel/air mix will have burned by the time the piston is 12 to 14 degrees after top dead center (ATDC); this will allow the most amount of useful work to be applied to the crankshaft, hence to the wheels."
I'm sure there is a better way to determine the curve than just guessing but it worked for me (no expert at this stuff by any means). Eventually I want to put it on a dyno and try to dial it in even better.
Hope this helped.
Gene