I tell you stick a 6.5 power valve in it and it will be way better under light throttle acceleration!!
since you will always be pulling over 2.5 inches of vacuum at light acceleration you have no power enrichment system so it will be lean.
Lean= ping

Your cam is no where near big enough to run a 2.5 power valve you only need one to 1.5 number in gear above the power valve rating to keep it closed in gear idle. so 9 - 1.5 = 7.5 but a 6.5 will work good.