I supplied my local machine shop with a 351w block and a pair of 302 heads...After The rebuild I've notice that 302 nor 351w spark plugs will fit in the head, it seems that ever small block ford plug I've tried isn't narrow enough to be screwed in. Before I call the machine shop in the morning, has anyone ever come across this problem?
are they 5/8 or 13/16 plugs. My motor has e6 heads and carries 5/8 plugs. I had some 5/8 ford plugs that wouldn't screw in because of the thred design and angle
Sounds like it is later model 302 or 5.0 heads. I cannot remember what year they went to the 5/8" plug but I think it is around 80-82. clint
I had an older set of 289 heads put on my 302. I had to go with smaller plugs, I believe I used an Autolite #45 18mm thread.
