I have now heard a variety of people and seen a variety of threads on the dangers of old 40+ year old hubs. I went with:
New Hubs by Goodparts – new 350$ per side, CV joint upgrades 699 – 749$ per side http://www.goodparts.com/shop/index.php?categoryID=20. Here is a site with pictures showing the installation process http://74tr6.com/axles.htm
We did a dyno test before and after thinking they might be more efficient. No difference. What did make some difference in the chart below was properly gapping the plugs. I hadn’t tuned it at all yet, wanted a baseline on the Dyno. Glad I replaced the hubs, feel safer now!