In case anyone missed the link, the manual is available and it's free.
Adding lubricant is mentioned here:
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0713.htm
Attachments
41f.jpg (68.82 KB, 132 downloads)


"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."