I'm in the market for a rough terrain forktruck for use here on the farm. I am doing timberframing and want to be able to lift multiple 600lb timbers. I've seen older tractors from the 50's and 60's that are forktrucks. Are those usually factory made that way or are the converted after the fact? What capacity do those typically have - 4000lb? How is the lift rating done? Rated with all the weight on the back of the forks? Or is it just the cylinder rating and you have to ballast the back of the forktruck accordingly? Any advice on going about looking for one? I'm interested in gas or lp. Gas I know I can work on. LP seems to be a little less maintenance from my experience. Doing a google search I didn't come up with much on these types of rough terrain forktrucks. Any advice on where to look? Thanks much, Brad