Dexta vs. Super Dexta

I was just a kid when the Dexta first appeared on the US market. I was always intrigued with the crisp sounding diesel tractor with two gear leavers. My dad operated an independent repair garage which included a lot of Ford tractors and farm equipment.
In recent years my interest has been renewed in the Dexta and Super Dexta tractors. This past Christmas I gave a Super Dexta to my 12 year old grandson and we are making repairs readying it for his use.
I am asking help to verify or correct some assumptions I have had about these tractors.
First assumption: When SN prefix changed to 960A was the beginning of the Super Dexta.
Second assumption: When the Super Dexta was introduces the Dexta was discontinued.
Assumption 3: All Dexta's have vacuum governors and all Super Dexta's have mechanical governors.
Assumption 4: All Dextas have 144 cid engines and all Super Dextas have 152 cid engines.
Assumption 5:All Dextas use a sweat collar to retain rear axle bearing and all Super Dextas use a nut.
I have found exceptions to my assumptions and would like to know the truth about my assumptions for these tractors. Thanks in advance for your help.
Jim

I will try and answer your queries:

1. Dexta Serial originally started 957E Diesel from 1957, Petrol from 1960 959E,
Super Dexta 1962, 960E/09A. In November 1961 all numbering changed and there is no
difference between the three, numbers started 09A and then changed yearly. To
confuse things even more they started using the same serial numbers with the
different yearly prefix.

2. No, the Dexta continued alongside the Super Dexta until the end of production in
1964.

3. Both Dextas and Super Dextas had Simms Minimec pumps after 1962. No Super Dextas
were ever fitted with the vacuum governed pump although there is a publicity picture
showing a Super fitted with one. This was a Dexta fitted with Super Dexta tin work
for art work purposes before the first Supers came off the production line.

4. Yes although over the years some have been changed. You may also find tractors
with CAV DPA pumps, these are MF35 engines that have been fitted after Dexta blocks
stopped being made and the engines needed replacement because of frost damage.

5. No, not completely true. The later versions had the same axle shaft and nut as
the Super Dexta.

It does get a bit confusing as originally the Super had dif. lock as standard and
the Dexta did not, then within a few months, Dextas came with dif. locks as
standard.

Thanks Majorman. That helps a lot and I may have more questions later.

I remember the advertising brochure on our 1964 model said it had the 144 cubic inch diesel w/44 belt hp and 38 drawbar hp. It had
the underslung exhaust by choice to avoid limbs, spin out wheels. We could bog it down on concrete for some reason. We ran it for 4
years and I remember the back main leaked and it was sent in for that, the battery was dead when it got traded in on a '68 4000.
The lift was problematic during those 4 years. When brand new the lift porpoised. The 4000 was one sweet machine...8 speed, ind
pto.