Hi,did mine last week. Your sizes sound correct, the cam is 7/8 , the oil seal,relaxed, is 13/16. I found the hardest job was getting the square section snap ring/ circlip off. I used a utility knife blade and a dental pick ! Loosening the cam gives enough clearance, careful getting the new seal on as it drops into the circlip groove, once again a blunt dental pick solved the problem. ‘The book’ says use no sealant but I carefully cleaned the seal landing groove and applied a smear of hylomar around the outside . All back together,no leaks. I prefer to glue my cam cover gasket to the cover and oil the head side. Much easier to clean it off the cover if you ever need to replace it. Oh ,,I also cleaned the pulley bolt and threads and added a couple of drops of blue locktite.