Etta block conversion

I have a '85 325e block. Can I put the 325i crank and pistons in it? I tried looking in ETK, But it only shows me a part # for the block with pistons!!!. How can I use the casting #'s on the block to tell me if the "E" block is the same as the "I" block just with different internal parts. I am not actually doing the "I" head on the Etta block. I have a blown motor and I also have an etta block. I have a rebuilt "I" head and want to put the "I" crank, rod and piston setup in it. WILL it work and how can I verify it???