Unless there is something drastic wrong with your head there is not much reason to switch to the later head. A lot of lip service is given to the "revised" chamber, but it really didn't amount to much in practice.
Any generation head will switch over, the big thing you have to watch for is the later solid heads used a different bolt in the rear rocker shaft hole for better oiling. You must use the bolt and rocker shaft that match the style of head. Everything else interchanges.
You can even use the '81 up hydraulic head, but you need the valve cover with it as it is different. The mechanical rocker gear bolts on, there will be no issues. Again, it will have the stepped bolt in the rear rocker shaft hole.
