TOPIC: Correct fluid for '62-'68 v-4 power tilt

I've been running type A auto trans fluid,but have noticed the tilt on the crestliner/evinrude will leak down slightly then stop and stay up for days. The tilt on the aristo Craft/Johnson will also. Could the fluid be foaming causing air to be trapped then compressing to a point and holding firm? Anyone know the correct fluid for these units??