Yes 10 jet sizes will cure any lean issues but not anything below about 1500 RPM or so.
I don't think my Cummins smokes as much as this thing would with a 10 jet size incerase.
Keep at it and you will get it leaned out at idle.
How much converter does the car have in it, how much does it pull down when you put it into gear? Also what is base timing at? I would likw to see at least 10-12 degrees with 40 or so total with good fuel in it.