Take off the rotor. If the distributor shaft is bronze, then its probably the Mallory built version. (The FBO plate does not work on that mechanism, the slots are internally adjustable.)
With some patience and careful repeated testing, you can probably get a curve out of it that will work with your 318. Those MP distributors are intended for hopped up engines which don't the low rpm combustion efficiency a teen has. That's why they advance so fast in the lower rpm range.
Post up what the situation is and I can get you started on a recurve.