i took a bolt to o'reilly's and they were able to size it and sell me the appropriate tap. i just successfully tapped the problematic boltholes, and now i am going to loctite the bolts and get the pulley and vibration plate in place. going to let things set / settle overnight before i try to throw on belts or anything (though with the holiday coming up, i doubt i'll get to anything til wednesday evening).

thank you again for the help everyone. i think my lack of confidence has been pretty evident in this thread, so any help is very, very appreciated. i'm sure i'll make some more updates as i re-assemble things.