i have a ofna blazer sst built off 9.5 chassis violiter i think any help on what engine i should drop in have .21 force now was wondering if and what .28 would fit the best or drop right in as my .21 force engine has stripped head button part num ofn52011 i guess there is none left in the world and also if anybody knows what parts will fit from what like a arms off the 9.5 will the fit please any help would be great and ty