This will likely come off like I'm an asshole and I'm sorry. Why are you so dead set on messing with this thing? It doesn't look like anything special, it's a factory serp setup, and a crappy TBI. If you want to make more power lots of things are going to hold you back, like the TBI, or the fact that it's an underpowered 305. For the amount of effort if you want any real power gains get at least a 350, your shit will all bolt up, but do something other then that weak ass TBI. Trust me you'll be happier, the way it sits I'd be shocked if it dyno'd over 200, why not make a solid 300+?
Okay I'm done ranting, carry on.