Great news Marty!
if the 900gr is tried and true, my advise would be stick with it. You center a rib on a ele you got problems. luckily there is more gap then rib.
Marty, *NB if you go the Tuff head be certain you have the best, solid well machined hardened BH adapter you can find. Most are crap soft cheap steel, and you will get this every time, and it will cost to an animal.
I have some of the really good 75gr adapters if they will work, i can send you what you need. If you need more weight you will have to source some.
Soft BH Adapters with Tuff head.
here are a couple pics you might like to get your mind around, if they are of some help.
Bull Ele