You're welcome, and if you happen to test drive another truck, the Chevys have a label inside the driver door that lists the vehicle payload and max trailering for that specific variant (model / wheelbase / tires / engine / options / etc).
A few of your numbers are off a touch. Unfortunately the spec section on the Chevy website is abysmal for these purposes.
The new Chevy Dually 4x4 will have less than 7442# payload - a crew cab Dmax dually 4x4 weights north of 8000# - possibly closer to 8800# if memory serves and the GVWR is...
Most modern long bed trucks can fit a tank in that size range in addition to a fifth wheel hitch. RAM has the largest footprint factory hitch puck system and my friend still fit a 90gal tank/box combo in his. The Ford & GM systems are a smaller layout leaving more room for the tank. KSH in...
You're welcome - keep in mind, that 4400# number is for a standard feature unit.
Listed elsewhere on the site is the options list and guess what common options are not included in those base weights:
Huge 5.5 kw Generator w/ 30 gal Gas Tank
40 gal Gas Tank w/ Pump Station*
Spare Tire / Rim /...
Don't forget that published weights from WW back in those days were optimistic at best. Going from a 'basic' LE series to a typically more heavily optioned CR is going to take away from the carrying capacity since almost all the 5ers of that timeframe were 16k GVWR (partly because most pickups...
If you are wiling to go 5er and older, the Gearbox 335FS could fit a Funco IIRC. Owned one years ago and had decent luck with it behind a '06 Dmax SRW truck.
Most tanks have ports going to the water pump fairly low on the tank but it could happen. Would think most all of those are self priming by design since they are almost always above the tank level in a trailer application. Make sure if you have any inlet screens that they are clear. Have had one...
Have you successfully done this with anything other than a regular car or truck? Attempted to do it couple years back on a quad and had issues, seems they are very selective as to what you can transfer online. Curious if it's improved or not since then
Good advice here on locations.
Only thing I would add is - don't drive your car off the asphalt! Even if it looks ok...it's usually not. Have seen more than one person slightly off the pavement at Osborne get stuck to the point of needing to be pulled out. This is made worse in the offseason...