The tools listed in the shop manual
were manufactured by Kent-Moore
for Chevrolet mechanics and Chevrolet
garages.
Go to e-bay and search under Kent-Moore
and they pop up regularly
they all have a number stamped on them that matches the shop manual number.
they will be advertised by that number on e-bay
I have most of the tools for the SM-420 transmission
Mike
they were purchased on e-bay