351 Windsor, which plugs...

[azfordman]

I have been trying to ID the motor set up in my car, a 90's era Contemporary....The motor in the car is a 351W, casting number E4AE-6015-FA7, which comes up as a 1984 block from a full size car/Galaxie. My problem currently is spark plugs....the heads use the old style "fat" base spark plugs not the new style skinny plugs, which according to the parts suppliers in town should not be used on a block this new (the fat base plugs), they were discontinued pre 70's. The plugs I recently put in the car seem to be too high of a temperature rating, Autolite 45's. Do I have to pull the heads off to ID them? Stamped on the top of the head with the valve cover off is "351", the ford symbol, and 4F5. The valve covers are a six bolt pattern, three on the top with the two outside ones just below the corners and the three on the bottom are more centered, two outside bolts not near the corners. Also it uses 7/8 bolts instead of the 1/2 bolts to hold the cover down. Any ideas? My only other choice on plugs is a much colder 124, which I think may be better, since a too cold plug will foul, but a too hot plug can damage the engine from pre-ignition. Thanks! Mark