hi, i am working on the rudder currently, attaching and riveting the reinforcment plate R606,607 and 608 to R-902. I realized that the AN740 rivets i used, i riveted them with the manufactured head on the aft side of the R902 spar. Do i have to drill them out? i figure the shop head on the front side of the spar will be covered anyways by the leading edge of the rudder, but i need to be sure. Any suggestions please?