Is there anyone that can point me in the right direction of what I need to convert from a vaccum to manual shift on my 59 3600 2 speed rear end?
Just a note that your 1959 "Viking" isn't a "3600" Series truck. "3600" Series (actually identified as Apache 36 for 1959) is the designator for a 3/4 ton truck. The 1959 "Viking" trucks were either 40, 50 or 60 Series trucks (40 Series = 1-1/2 ton, 50/60 Series (Special) = 1-1/2 ton, 50/60 Series = 2 ton, 50/60 Series (Heavy) = 2 ton).
For some original detailed info on your truck (which ever series it is), you may want to read through this original
1959 Chevrolet Truck Engineering document. It will shine a lot of light on information on your truck.
