oring chain question?

[panaceabeachbum]

Just curious if 520 oring chain can be cut, shortened , and reattached with a master link. Changed to 13t front on 650l, ordered a new chain and master links but the chain is an endless loop and the masterlinks I ordered are not going to be long enough to extend far enough thru the side plate far enough to get the clip on, the chain didnt come with a masterlink either and I am just not sure how to proceed. Whats the proper link count for 13/45 combination? would 14/50 or 14/55 be a better choice? All my riding is dirt road, just trying to actually make 1st gear usable in the dirt. Thanks