I just confirmed that 32-41 cams are approx 3/8" longer than 42-48 cams.
hence your problem.
The cam is holding the dizzy out from the face of the plate as the crab has a longer nose.
In 1942, the longer cam was discontinued. Anyone who needed to replace a cam in a motor with a divers helmet dizzy required a spacer button inserted into
the end of the 1942 camshaft.
You should grab hold of the front of your camshaft with a pair of pliers and give a wiggle, as
you may simply have a spacer button in the end of the camshaft.
If you have this button spacer simply pull it out and everything will fit.
If not you need the 2 bolt spacer Part# 9104248 (
http://www.ebay.com/usr/speedway_mot...p2047675.l2559 in the USA) which will fill the gap between mounting plate and the face of your dizzy.