Quote:

48 degree babbit blocks are not stepped journals ........ they take their own bearing sets and are all the same diameter.
http://www.jegs.com/i/Mopar-Performance/312/P4876372/10002/-1?parentProductId=1903872

I am pretty sure the 59 degree blocks use the stepped bearings like the stock blocks.



That's not correct. The early48 deg "r" blocks and "r1a"blocks used stepped journals like a 59 block but with 48 degree lobe spacing.
I have one and it uses std small block cam bearings.
Call bullet or midway cams.