One of the guys on HAMB got me some numbers
1976 catalog:
306 MECH Revmaster
Intake 39-87
Exhaust 87-39
Lift .532
Valve lash hot .024
Duration 306
No reference found to X74.
Extrapolating those numbers, that cam is 114 LSA on a 114 Intake centerline.
Guessing at .050 duration, I'd say likely 240-ish, maybe as high as 244
So is the cam any good?
Well, it is a very old school 427 cam, with 78 degrees of overlap, it'll sound good out of the pipes.
It will also likely feel fast, BUT, the low lift will leave power on the table, as will wide LSA compared to a modern cam. Additionally, it would likely need to be advanced as much as 8 degrees with a modern 9 position chain for it to be happy with an 11:1 482.
Really the cam could be fun, but if you are going for high dollar heads, the lack of lift wastes a lot of airflow. If you just want old school cool, you could set that cam up on 106 ICL, port the hell out of your iron heads, and put a dual quad on top with a set of headers, but a modern cam would be stronger and almost a requirement if you spend money on modern heads
