pinging and smoke under load

Ok, I've been having an issue under heavy acceleration. The engine will ping and I get a lot of grey smoke. Otherwise the car runs great. I've checked the timing and replaced the bushings and springs in my dist. I'm using the biggest springs the kit came with. I'm wondering if my secondary jets are too small. I can't remember what they are but am thinking 66s. I haven't tried increasing that but might be my next step. I'm running 10.5:1 compression and should be ok with 93 octane. I'm not sure what else to check other than that. Any suggestions would be helpful. Thanks.

Oops, forgot to mention: Engine is a bored 289, .512 lift/292 duration cam, heads have been ported/polished, heads and block decked. Can't remember valve sizes. 570 Holly Street Avenger carb, Edlebrock Performer intake...

It's a lot more smoke than I would think would be from a rich mixture. I may be wrong but I will try some Marvels and see how it responds.

No, I'm not getting that but I know exactly what you are talking about. I used to get that with my old carb. I've rejetted the primary jets, replaced the distributor springs and bushings and reset the timing. It helped some but still does it. Since it occurs when the secondaries open I'm wondering if I need to change those jets.