timing..pinging ??

i tried to unplug my timing advance and adjust the timing but nothing is helping my ping go away. It happens right when i switch it into 2nd gear from 1st in higher rpm's. If i advance the timing near 16 and leave the timing advance unplugged, the ping goes away. I was maybe thinking it has something to do with air fuel mixture? because the car used to be a 305 tpi, now its a 350 tpi, but still has the 305 19lb injectors. also it may need a chip for a 350?
the car runs pretty good, its just that little ping for a second thats pissing me off. I always run super, 93 octane, and i tried octane boost with no results.
thanks for all the help!!!

New set of 22 pph injectors and a custom eprom.

i am getting the holley stealth ram so i will probably get the 24lb injectors and a custom eprom.
thanks!