need advice quick!

[67pro-street]

i was changing the spark plugs on my engine and i was putting in the last plug when i accidentaly screwed up the threads on the engine. What should i do to fix it. I didnt screw up all the threads. I felt it turning kinda hard so i backed out the plug and it only screwed up like the first thread. So would i be able to just get a tap and fix the threads. And can i just leave everything together, or do i need to take the head off to do it. any help would be appreciated. I need to get this thing running soon as it is my daily driver.

thanks,

67pro-street