That is correct Steven, however I'm guessing that while the heads might look the same the combustion chamber on the 865 would be slightly bigger in capacity to achieve a 9.2:1 compresion..because if you bore a 790 out to 865 and use the same combustion capacity you would wind up with a higher compresion, exactually what a big bore kit does..those more mechanically minded than me might want to chip in..
