Engine internals...

Evening all, 

Your expertise would very much be appreciated once again. I have a spare engine short block that I picked up cheap and I wondered if you could help me identify the internals. 

The rods have BKG KG6 and B1R 1R7 stamped on them. I've looked at the bottom of the pistons and they are smooth so I believe that means they are forged. They also have HF stamped on them. I did also see what looked like -4 on one, but the block is still assembled so can be hard to see.

Any advice would be great!

Thanks in advance.

Trev