OK, new rebuilt 1955 Mercury 292 w/mild cam, and rebuilt medium case FM tranny.  My engine builder recommended Jo Gibbs racing oil w/ZDDP for break-in.  The literature he gave me also recommended at initial start-up to immediately run engine at 2500 RPM for 20 minutes.  But what about the transmission during this time.  Is fluid circulating in the tranny in Park??  I ran engine about 4 minutes and thought of the tranny implications and shut her down.  Any help will be greatly appreciated.

 55 Sunliner

Gary