What you have is a ’47 3.3 horse opposed twin motor. The ’48 and later 4423 Sportwins were inline alternate firing motors. It originally called for 1/3 pint of oil per gallon (24:1) but it might be better to use a bit more oil. 1/2 pint per gallon would make a 16:1 mix. It spins a 7 X 5.5 inch two blade aluminum prop with a 3/16 X 27/32 hard brass shear pin. The plugs are gapped at 0.025 and the points at 0.020. The 171449 condenser/capacitor should read 0.010 uF (mfd) with an allowable +/- 0.02 uF.
Here’s some more info on your 4421.
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