Paul and Steve,   Steve gave me a prop flange to firewall distance of
39.5"  I am trying to reconcile this with the measured cowl length of
41 inches.  It may be that there is  an extra 1.5 inches that can be
added to the prop extension while keeping the engine at the proper
distance from the firewall.     Jerry

I am not going to redo that motor mount again :) I almost have it
done. Just stick the cowl on there and measure what
you need before you order the prop extension.