2nd that... That cam, combined with a single plane intake will give you major headaches below 2000rpm and power brakes would be out the window. You will not have any vacuum. Ironically, the 273 heads might actually help...the restriction would aid in preventing all your air/fuel mixture from flowing down the exhaust pipes before ignition.
I am doing a very similar "budget minded" approach. Something that is extremely hard to do once you get rolling. You start to realize that even a simple tear down/rebuild calls for replacing so many parts. Other wise you have a high mileage, pretty, clean dog.
I am by noooo means a pro. Honestly, I am still a novice. I read a great article a few years back (Popular Hot Rodding - July 2006) about camshafts. It helped me to understand the concept of how and why an engine works and therefore how to make it do what you want.