Marina 1275 A (not A+) engine - going on a 1098 box. I have modified the 1098 flywheel to fit the crank ok - but in the crank tail there is a little roller bearing instead of the oilite bush in a 1098 engine. The gearbox shaft is 1/2" (actually .498") - and the roller bearing 'appears' to be 1/2" - but it could just be 13mm - I don't have any accurate means of measuring it up inside the crank and to take it out will ruin it. Anyone know if it is 1/2" ID - and will the 1098 box snug up to it ok (using 1098 backplate of course)??