Help identify 360

Yea I'm stumped. There are some punched numbers right below the heads but they make no sense. Ill post some pics later. It does look like it could possibly be a roller block. It's got a girdle in the lifter valley which I've never seen before. It's been a long time since I've had to rebuild my smallblock so I'm a little rusty and I've never rebuilt anything later than 70 LA motors. Thanks for input guys