Yeah, come to think of it, I once tried to flat tow my buddies old 1972 190 Mercedes Benz with a little 4 cyl powered mini pickup (another buddies) many moons ago..  I think it was an Isuzu or something..  And it was up a slight incline with just a tow strap on the Benz and I had to slip that clutch something serious and I know I burnt it...  I ended up having to flat tow that Benz another time, but I had to use my 1986 Mustang GT with a 5.0 V8 and 5 speed manual in it and it did it a lot better than that Isuzu..  (up the same incline street too!)
So, I might have been a bit generous in my original post saying your Yota should be able to handle a full size #3500 TT.... 
I agree, a #2500 pup up would probably be all that a 26 year old 22R 4 speed can handle with any sort of longevity in mind...
Mitch