Interesting that the ST-15 cam has a lot more duration, but a lot less lift, than the ST-14.
When I overhauled my 65 Barracuda's original 273 back in 1971, I used a TRW solid lifter cam which, going by memory, was 284 duration, .426-.422 lift. Have no idea what the duration @.050 was, but at least on the surface, it appears to be quite similar to the ST-15 cam. It sure woke that little 273 up.
After I blew up the 273 in November 1972 trying to drive home to Cochran, GA from Charleston, SC in second gear (after I broke the 3-4 shift fork), I pulled the TRW cam out of the 273 and ran it in the 340 I had swapped into the Barracuda to replace the 273. The stock 340 cam would pump up the lifters if I overrevved it just a little bit in low gear, and it would be halfway through second before it fully recovered. The solid TRW fixed that problem, and made a little more power to boot.