10-39 = 3.90:1, standard 1/2T ratio, the grinding is the usual factory cleanup of the rough casting

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics