The 5-T flathead cam was the early 21 stud grind and lasted to the last 59a engines. From 1949 thru 1953 (1cm, 8cm ,eab, eac etc ) cams all had minor lift and duration variation's from the 5T grind. However, Don't expect to see much improvement in power and/or economy. I like to use the sab/eac with valve rotators and short valves. They would probably work with the long valves, but you'd have to puts with the spring pressure. 50 lbs is more tha enough for a stock engine. I only use 60 lbs for the L-100, seems to work Ok,
Gramps