On the car I mentioned above I added timing up to 40* before it stopped speeding up. It's set at 22* now and it's limited to 34* max. The car has an Edelbrock Torker intake and a 1" spacer with 10" or vacuum. Big plenum area, low vacuum to start, no vacuum at all once you crack the throttle, increase the squirter by 3 and tune the cam to provide more fuel. The carb book I used (by Dave Emanuel) has pretty much those exact words in it.
I fell into the trap of thinking I was going to end up pulling the motor apart to check the cam and/or replace it until I calmed down and worked the simple stuff.
