Need help with 307 - 350 conversion

Ok, I just bought my wife a 73 Nova Custom. It's got the 307 w/ 2bbl rochester/TH350 in it... Here's the project, my wife says to me, I want this thing to destroy rice-burners on the street, (I think she means the amateur kids with their "reed-equipped" mufflers and such, but I see what she means, they are annoying) We don't have alot of cash to throw at it all at once, but we'd like to make it a progressive project. I came across a rebuilt chevy 350 w/ TH350 for...$350. I want to throw it in there ASAP, but I'm not sure exactly how the other stock parts with react to it, let alone the upgrades that might come out of it. My main concern right now is the rear end, transfer case/differential/axle, will I need to swap any or all of that stuff out? I'm pretty good with mechanics, I've just never dealt with this issue before though. Any recommendations as far as parts needed and sizes for max power would be helpful. Thanks in advance

its a direct swap and the rear end and the rest of the drivetrain will be good to at least 400hp under normal driving/street strip action have fun!