GM put a 3 digit casting number between the lobes on OEM cams when they were original production and many service cams. The last 3 digits of the number of the CASTING is frequently very close but not the same as the PART number of the camshaft assembly. If it is an original GM part, these numbers will be there. If it is an aftermarket service replacement cam, it may not have the same last 3 digits of the casting number cast between the lobes.
I suspect you have an LT-1 solid lifter cam. That is a real good street/strip type solid lifter cam design for the first gen SBC. You could pop it into a block, throw a lifter on it and check the lift with a dial indicator to verify it. I have a cam card for it if it would help. Just send me your email address in a PM and I can send it to you.
-Mark.