Tom,

I've seen the Chevrolet vacuum push/pull and the Eaton red knob push/pull switches (https://www.amazon.com/Four-Seasons-35802-Speed-Switch/dp/B000DCNFAM), but never seen the knob the OP has on any Chevrolet TF trucks...must have been a GMC thing...could it be Timkin related?

Mike B smile


Mike Boteler

1956 Chevy 3100 Resto Rod
1952 Willys M38 Army Jeep
1983 Jeep CJ7 Laredo
1984 Jeep CJ7
+++++
Silver Spring, MD