Question for the guys running aluminum heads

[tubman]

My memory is returning. I think we ended up using Champion N-5's. A lot of people don't like Champions any more, but I'm sure NGK has an equivalent.

Pete, if the used heads I bought in 1961 were 3/4" reach, the change from 1/2" reach must have happened a looong time ago.

[Pete]

Originally Posted by tubman

Pete, if the used heads I bought in 1961 were 3/4" reach, the change from 1/2" reach must have happened a looong time ago.

Probably in the mid 50's or so. The last set I bought was in 54. We used to put 1/2 inch Helicoils in new heads so we would never encounter a pulled thread when changing hot plugs at the track.