Martin, The 300 is at least equal to a 292. Some say better especially the late injected ones.
The local feed store delivered hay to me 2 tons at a time until he replaced his old 292 powered truck with a newer V8. A friend loaned me a '42 Chevy dump truck with a 292 in it. Loaded to over flowing with gravel it came up our steep 2 mile road and did not need the granny gear and mostly not 1st. Another friend had a dump truck with a 292 and he hauled and pulled and equipment trailer all over this area including trips to Lake Tahoe. Other guys borrowed his truck for tough jobs. My old '40 International hauled many 3 ton hay loads up here from all over this area and a dismantled barn from over the Sierras. It had a 261 International inline and a 16' bed. In an earlier life in California it hauled a trailer, both loaded with cattle. These ate truck engines. They pull and haul.
For you gears will be the important thing to enable you to have the power and fuel consumption you will want. As far as power it won't know a 1500 LB trailer is hooked up.
