There's a difference between the E/f350 and what engine is installed. The E350 relates to the chassis size and weight. V-10 is the engine size. I've got v-10s in both my E450 motorhome and my E350 passenger van. Van pulled a 9000lb trailer over the west coast mountain passes without a problem. E350 is rated at 1 ton cargo, same as the chevy 3500s. Desert Captain, counting cylinders in an E series van isn't as easy as it sounds.
I was dissapointed with the towing capacity of the the motorhome, but looking underneath the unit, I can see why the limitation. I've seen lots of people towing race cars, so I assume they beef up the frame to compensate. My van is rated at 10k so it's not the drive train.
if you are unsure of the configuration, find a vin converter and it will tell you what's in there.
1998 Class C Lazy Daze 26 1/2 island bed
banks intake/exhaust
wifi/4g/siriusXM/DTV/DirecTV/CB
2xGeorbital electric bike conversions