How to make a 240z FASTER?

I'm considering buying a stock 72 240z, and am wondering what I would need to do to make it run about a 14-15 quarter time. I am wary of the v8 conversion because I would still like to keep the weigth down for handling, and it seems like it would be a hassle. I am not well versed in the datsun engines and would like to find a source for info(website?) that could outline how to build a nice engine. Could I use the stock block? Also, an estimated price would be nice for each suggestion. I would probably be content with a little over 200 ponies, but I welcome all suggestions. Does anyplace build these engines for you? thanks