What is the needed air intake for my retort which smokes like crazy?

I have a 30 gal. drum with 4 holes at bottom, inside a 55 gal. drum that has 16, 3/4 inch holes at bottom and 8, 3/4 inch holes at top. With 48 inch stack. Using DRY wood I get an excess of smoke through nearly the entire process. Makes good char but as I understand it, it should not smoke at all. Do I have enough air coming in?

As a guess you do not have enough secondary air so you are no reburning the smoke containing the volatiles. Look up on YouTube gary gilmore's charcoal retort videos. The two barrel system is very easy and the barrel in barrel system is also improved by using his barrel on top secondary air reburner. I make biochar for running engines like gary does but the process is the same.
Best regards David Baillie