Timing and balancer help!

[kcstreetracer]

Ok fellas, I have a truck I've been building the past few years
And have it to the point I'm ready to get it running. But I am having some timing issues I believe.

I have it close enough on timing that it runs. But I can't get much run time because I'm worried it has some pre-ignition or detonation. Its not rod knock I'm sure of. Basically as the cam lopes as it fires it pops and it sounds like its coming out of the carb. Its not every cycle but almost. I've tried turning the distributor but no luck.

Motor is a 355 with 234/488 cam,sportsman 64cc heads,single plane,fts 750 mechanical secondary carb, hei with heavy and light springs.Have 93 octane in it. I believe compression is probably around 10 to 1

I'm not sure if my balancer is correct for my timing tabs. I can't seem to find anything solid on it. The # is 7704 which i believe is a pre 69 8" balancer? My timing tab is bolted on the cover and tdc is about 2 o'clock. The timing mark on the balancer is just a hair to the left of the keyway. I originally had dropped the dizzy in at tdc, but redid it to what I believe is 8° btdc which seemed to help a tad. Starts easier and idles a bit better. I have a piston stop coming to try and get it but this is all new to me, although I'm pretty decent with a wrench the old school stuff is new to me. Im just wondering if my issue is what I think it is or if I need to focus my attention elsewhere. Thanks