bob58o
SuckSqueezeBangBlow
Seems like you are close to knowing what you need.
(2) 1-5/8" OD, 5/8" ID bearings....
5/8" Jackshaft (how ever long you need - length of JS housing plus room for driven unit, sprocket, and lock collars)....
5/8" lock collars (to hold the driven unit on and maybe the sprocket)....
New Belt (for the new distance between the crankshaft and the jackshaft
(2) 1-5/8" OD, 5/8" ID bearings....
5/8" Jackshaft (how ever long you need - length of JS housing plus room for driven unit, sprocket, and lock collars)....
5/8" lock collars (to hold the driven unit on and maybe the sprocket)....
New Belt (for the new distance between the crankshaft and the jackshaft