336 mount height needed for 40mm scope

Ok some of your probably saw my post last week about scope recommendations for my 1970 marlin 336 texan. well i ended up buying the cabelas lever gun scope and am trying to figure out what height of mounts i need to clear the rear irons with this new 40mm objective.

id prefer it to be as low as possible without causing an issue with the hammer and rear iron sight.

what say you? feel free to post picture of your setup

actually already has the jm hammer extension. the old lyman scope finally gave up on me and moves the reticle after every shot.