Yeah, Pixman nailed it. Grinding off the chrome would have been step one. I don't even want to think about the cost of a carbide tap. 
I'm not all that familiar with MAPP gas, so I had to look it up.
It appears that it burns at around 2000° F in air, so that should do the trick. You need around 1400° F IIRC.
Heat the spot where you want drill/tap with your torch (inside and out) and get it glowing red. You can use a small magnet to test it for the right temperature. When the magnet no longer sticks to your "spot" you are there. Keep it there for a minute or two with the torch. Then drop your socket into a bucket half-full of ash or sand, and quickly cover it with more ash/sand until full.
Let it sit there for a few hours until it has completely cooled off.
That's the quick and dirty home shop method anyway.
I'm not all that familiar with MAPP gas, so I had to look it up.
It appears that it burns at around 2000° F in air, so that should do the trick. You need around 1400° F IIRC.
Heat the spot where you want drill/tap with your torch (inside and out) and get it glowing red. You can use a small magnet to test it for the right temperature. When the magnet no longer sticks to your "spot" you are there. Keep it there for a minute or two with the torch. Then drop your socket into a bucket half-full of ash or sand, and quickly cover it with more ash/sand until full.
Let it sit there for a few hours until it has completely cooled off.
That's the quick and dirty home shop method anyway.
Willie