it has a 6 speed alison and I believe the trans warranty is longer but I am not sure I would have to check. yes it is transferable.

This is my third truck with the cat/alison combination and never have had one break, then again I do my routine maintenance and pull within the trucks specs.

It seems to me that the modified mediums are all grossly underpowered with cat 3126 or equivalent 7 liter sixes and are built on a dump truck or box truck chassis that is designed for slow speed local deliveries, not launching boats on ramps or driving in traffic. They are never offered as 4wd unless modified by some local conversion shop.

It's not the engine size in a medium duty, its the trans and rear end gearing. IH makes a 4X4 and so does Sterling.

750's are the 4x4 version and seldom seen because of the hard ride and the 2 wheel drive 650 with traction control does fine in snow. never has a problem at the boat ramp and are mostly seen as rollbacks or box truck chassis. Will run over 100mph and pull a boat all day long at 75mph on cruise control at an acceptable rpm.

I am confused if a truck is designed for local deliveries then wouldn't it be good in traffic and have a low gear good for a boat ramp?

It might seem to you but I am telling you first hand experience. Ford 450 has an International motor, enough said.

Is the 650 as quiet in the cab as the new 2008 450?

It depends how you spec it. The 210 horse cat is usually what's going into these 24' box trucks or rollbacks. The 330 horse RV/fire motor is going to have almost twice the torque. Naturally, it's going to burn twice the fuel- thats a problem for the average business that's using their trucks to deliver furniture. The 330 in a 650/KW/FL, etc will drag a 20K boat/trailer up a grade significantly better than any light-duty.

I rarely see the 650 with a 210 cat, it usually a 330. The truck also comes as a 19 or 22 inch wheel truck and is geared accordingly.

210 for sure would be underpowered in my opinion.

I doubt it, but one is a truck that can pull heavy loads and has the braking and trans capable of heavy laods and safe traveling. The other is more of a daily driver that is capable of towing. You started this thread saying you had a 21k load to pull. If that is the case you want a 650, if not a 450 might meet your needs. I would not us a 450 to pull a 21k load in any case unless it was down the street to a local boat ramp.

There have been several entries on recent threads that compare the Ford F650 to the Freightliner FL70 Sportchassis. They seem to strongly favor the Sportchassis for ride, stability, warranty, service, and dealer network. Do you agree?

Most of them (mediums, not the 650 specifically) made that are sold to fleets are, whether it's Cat's, Cummins' or Inl'l's. The specialty chassis usually get the big motors. The 330 adds cost to the vehicle and cost to operate, which is an even bigger consideration.

Fleet owners are very cost-sensitive, sometimes to their own detriment. I have a customer that has almost 3,000 Fore E250's and every one of them has a six in it. 80% of them are carrying 1,000+ lbs over GVWR. They buy replacement engines for them by the semi loads- they just aren't up to the job. Their fuel costs are lower- maybe enough that it makes sense to them.