1973 340, want more power.

Richard McLaughlin said
It is a street car. I would like to be able to do a few 1/4 mile runs. But 99% street car. I want to make it just as powerful as a 6.4l srt basically. Or around there. Maybe that is not realistic.

So from my quick google search, it looks like you want a very street friendly ("99% street car") mid/low 12s.