360 hp e58 ?????????????????????????????

I have a 360, was told it is an E58 Police engine. Its a 1977. On the front of the block under the head reads 2556 in large letters. then upside down in smaller letters w3 o HP, not sure if any thing between the 3 and o as part of the larger 2556 is in that area. With out taking the engine apart is there a way to tell if it is a E58 engine. Tried to get pics of the numbers, to small for my camera...........Thanks if you can help.