[Chifo Jr]

I did the initial startup of my 70 351C. Fired and ran great within a few seconds of the turn of the key. Then things went down hill. I noticed leaking around the spark plugs. Upon inspection the heads have a flat land at the plug thread and the plugs installed are beveled without a compression seal. Obviously not compatible. Unfortunately 4 parts stores all call out the plug which is obviously wrong... Any help or numbers for the right plugs?