broke off tap--help

yesterday i decided to work on my 360 yesterday i have some little things to do on it. im running 2000 daruang exhaust manifolds and i notice they dont cover the air injection ports on my smog heads. well being the mechanic i am i busted out the tap set and going to tap the hole and stick small studs in the hole and plug them up. unfortuly the fist one i tried to tap i snap off half way in the hole. well i tried drilling and crushing the tap. i keep going im going mess somthing up. question is can i just j\b weld the hole and go about my busness or do i need to get it out. if i do how


thanks for any help bryan