I think they did to a degree. For example if you compare the lower A-frame
bushings of the first 122s (which are like the upper A-frame bushings) to
those on the later (68-69) 122s you will see a tremendous improvement.
Other matters like the driveshaft center bearing, rear suspension,
engine improvements, etc were upgraded through the years. Same is true
to a degree in the 140/164 series, also in the 240s, although I don't know
as much about them. Looks like the biggest problem with the 240s is that
you gotta keep changing timing belts and the heater fan motor gums up and
seizes, then burns out. That is really more of a lube problem than a
design problem though, and it happens on all kinds of motors. Biggest problem
with them is the fact you can't get at them on the 240 (or 140/164 either, for
that matter).

Did you stop taking tokens?
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma