[AnthonyG]

To answer Frank, porcelain looks pretty good. 2000 + or - miles on them & their a nice toast color. I’m not sure whether 437 Autolites r extended but that what the ones shown r. Not sure the # of threads means anything as long as the arc pedipalp & ground hook r located ok. In this case as measured the arc pedestal is flush to the head chamber surface where it protrudes & the ground hook is entering approx .100” beyond the durface. There’s no indication the valves were bumping them after 2000 miles.