I have a '54 6100 Dump Truck. It still has the straight 6 235ci. Has anyone swapped in a bigger motor? What are my options for a bigger motor if I decide to swap? I use my truck to pull a 20' 10,000lb GVWR trailer w/ my Kubota Tractor. With the trailer and tractor the total weight is 7500-8000 lbs. Plus sometimes I would like to go a little faster down the road.