1956 wide frame clutch problem?

hello everyone ive rebuilt a wide frame engine new crank shaft, bearings the sip barrel kit new ignition and sip clutch starts up lovely no weird noises.
problem is without bike running put the bike in gear you can push freely
if you try to push bike backwards clutch will not disengage ?
start bike up and put in gear clutch drags really bad to the point of stalling
ive tried machining case, case spacer and sip clutch modified centre and taller pushrod, machined the clutch to allow more clearance ?
some one on here had similar problem years ago i did comment on his post but no answer has anyone had this problem am i missing something ?