You haven't mentioned whether this engine is relatively new or very used. Good compression means that if you try to turn over the engine without a prop it should be difficult. If it turns easily and only has a mild hesitation during the power stroke then the engine is tired and needs an overhaul.

If the engine is of the earlier design, they had problems with chrome liners pealing -- this robs the engine of compression.

This engine thrives on all FAI fuels. My personal preference has been 15% Wildcat.

Finally, my glow plug recommendation is an OS #3 -- have seen that plug solve many problems with relatively new OS FX .46s.