No shift motor on the left side as far as I can see.

https://goo.gl/photos/mp5WcJwcbX5BkSLv8

Probably it has been removed in the past.

Now I hope it's locked in the high ratio to be the least slow as possible. Otherwise 30 mph will be my top speed...

Haven't driven the truck for more then a 1/2 mile straight so no idea what the top speed is.

'52 Cadillac Coupe de Ville (to be restored)
'56 GMC 450 (work in progress)
'79 GMC C15 (fully restored)