Advantages - specs on Full Auto cylinder head

Hello all, new to the site, but with a long passionate history for Nortons, along with other old bikes. 

Finally I have purchased a '72 Commando basket case which I thought included a Combat engine, but does not have  'C' stamped on the head. I am very focused on taking advantage of the Combat head and road one that had the ports enlarged to Dunstall specs. I experienced the improvement in performance with this as any engine improved breathing with reap rewards.  Now I have learned about a FullAuto head, pretty pricy, but have not been able to learn anything about the advantages______?  Does it make sense to pursue this newer Full Auto head or could I gain the same flow advantages with modifying my standard 750 head? One person told me that the Combat head had different valve angles which added duration / overlap.  

Any and all information as detailed as possible would be a great help in determining which direction I should go.  Thank you