Making power in a 289

[KiltedBanshees93GT]

Right now I am looking for suggestions as to the best ways to make (preferably low money) power out of the 289 engine. Since I never really followed the "classic" Mustang tech, I'm not sure where to start.
In general, I am looking for the equivilent of the basic "bolt ons/tricks" that I know for 5.0s. I'm already going to check the timing, and generally try to tune the car up, but anything else will be a great help.
I've also been thinking about going w/ 351w heads, I've heard and read that they are good for a bit of HP for cheap, why? My understanding is that the bowl design will up the compression, is this correct?
Like I said, I'm not really sure where to start.
Thanks for putting up with my many dingbat questions,
J


BTW, the engine was originally a 2v 289, converted to a shelby hi-rise manifold/Holly 4v, and I dont know what the current cam is.