48 3/4 ton wheel and fuel pump question

[jp2112]

My grandpa recently gave me his 48 3/4 ton pickup, and I'm in the process of fixing it up and making it driveable again. It has the 8 lug split rims. Also it does not have a bed on it. It used to have a wooden flatbed. I would like to put a metal framed flatbed with a wood floor. I would also like to make it dual rear wheel, to have something different. I saw where most 8 lug stock wheels from chevy, ford and dodge would fit but will the dually wheels off of any of those work? The rearend appears to be some type of full floater... Also the truck still has the original fuel line and fuel pump with the glass bowl on the inline six. Is there any modern pump I could put on there? Oh yeah forgot to mention, I'm new here. This is a great site with a ton of info... Thanks JP