Great pictures of those beauties!
I was lucky enough to attend the meeting in Oregon a few years ago.
I sold my big V6 powered motor home (still shown on Jolly's old list of "Powered by GMC V6" ). The stiff clutch was just getting to be too much for me at my age.
The extra 478M engines are gone, so I have no need for the
very heavy duty engine stand. It is a slightly older version of the current OTC 'Motor-Rotor'
https://www.amazon.com/OTC-1735B
Rod Johnson
P.S. I am still selling the occasional Buick HEI conversion bushing kit ( about 1 per month), so there is still demand for these old motors