Ported head and bigger valves

so, I dunno if I'm going crazy but, every since I ported my slant six head and installed bigger valves it seems that I been able to add more initial timing With out pinging, can this happen? I do remember that the cylinder head I had on before was choked my motor and wouldn't pull hard after 5,200 with all that casting flaws blocking flowing and un matched ports. The motor has 9:1 compression with 3.55 gears