Blowing Glow Plugs is a sign of a Lean Run, or an over compressed engine.

Double check your low and high speed needles. With a Fox, I would aim for at least a 500 rpm (not 50) drop from peak. Also, 16% oil may be a bit on the low side for this engine, I would suggest a minimum of 18% and preferrably 20%.

If none of this works, consider adding a 3-5 thousandths head shim.