1443 5 wheels per track. Maybe because pontoons were still standard and this was and option back then?
Your stamped data plate is interesting. I'm very curious as to the actual weight of your Tucker. I'm suspicious that the listed 4,600 lbs is the weight for a pontoon equipped machine. I say that because I have a Tucker 1500 series brochure and spec sheet dated 9/78 and it lists the unladen weight as 5,970/6,310 lbs (undoubtedly different cab configurations).
Further on it lists "Engine: Standard, Chrysler 318 CID V-8" with no optional engines available. For transmissions it lists "Transmission: Standard, N.P.G. 540 (5 Forward/1 Reverse) and two automatic options a Chrysler A 727 and an Allison AT-540.
I also have another 1500 series spec sheet dated 10/83 which lists the unladen weight as 6,340/6,560 lbs. And it also shows the 318 V-8 as the standard engine with the 360 as an option with two Cummins options as well.
I'm thinking the rubber track system weighs more than the steel track/pontoon system (and may require more power to turn it). I suspect Tucker then decided to use the 318 because of the extra weight/power requirements, but that's supposition on my part...