I stand corrected on the T type plug. The tapered seat was started in about the early 70's. I do prefer the S type plugs with the extended tip for o-head valve engines. They came out around the early 60's. All the car manufactures immediately started using them.
I am sorry if I mislead anyone.

George

They say money can't buy happiness. It can buy old Chevy trucks though. Same thing.
1972 Chevy c10 Cheyenne Super
In the Gallery Forum