To be able to adapt to a Fluid Drive setup you would need an engine with an 8 hole crankshaft flange and a Fluid Drive bell housing, with a Fluid Drive unit, to go along with your long input shaft 3 speed. As your truck is a 1 Ton it should have a 230 CID engine, so the 8 hold flange may be there already. But unless you already have the bell housing and FD unit it's not worth the effort to convert everything. If you want to use the other 3 speed you'd be better off finding a standard input shaft, and bearing flange, and convert it over.
I will say there are some advantages to having FD in a truck. Less clutching in city traffic being at the top of the list. And yes, a working parking brake is a MUST.