I am currently in a little bit of a planning stage to get some more power out of my GTA. At the moment I am just sort of tossing around ideas and I would like some input on some of this. Before It happens because I know it will, I am not doing a LS swap, or an LT swap, or at this point a 350 swap. I am going to stay with the 305, at least until it lets go. So here are my plans:
Full bolt ons, Runners, plenum, intake base, intake, headers, y-pipe, high flow cat, and a different cat-back because I am not happy with the one I have on there right now.

In addition to that I want to swap in a 3.42 Disc rear.

Now in addition to all that I want to do a heads and a cam to open it up that much more. Keep in mind I will be keeping all emissions stuff and I want it to be able to pass. Here is where it gets a little tricky. As for a cam I am thinking about using a ZZ4 or equal cam with 1.6 or 1.7 ratio roller rockers.
As far as the heads go I have a few options. I have a spare set of 305 TPI heads that need to be cleaned up and ported and swap in a little bigger valves. or I can go with a cast 350 TPI head, or a aluminum corvette 350 TPI head, both of which would at the very least need to be ported. Can any of those handle a ZZ4 cam?

Or I can go aftermarket with something like the Edelbrock E-street SBC heads. but I am not sure if they have the TPI bolt pattern. I would like to use something that would accept the factory TPI bolt pattern. It's more cost effective for me to open up the TPI base and bolt it on then to have to buy a Vortec style and then still have to port it anyways.
Thats what I have now. Comments and suggestions are more than welcome and if you have a part in mind that would be a good fit and is what I am looking for let me know.

 

I built a 305 a few years ago; SuperRam, World SR 305 heads, 268xfi cam, roller rockers....the whole bit. Then I put a procharger on it.

Curious why you want to stick with the 305 and not swap a 350? Everything you bolt on will make more power on a 350 vs the 305. 350's are cheap too!

 

The combination of parts that you have will wake up a TPI engine. Make sure you get a custom tune with your final engine combination. With the changes you listed the stock computer tune won't like them very well.

You are going to hear a lot of people tell you to start with a 350. It's true that you will make more power with a 350. If you want to keep the 305 until it goes thats cool to. It would be working with something that you already have. I would just make sure that you select components that could be transfered to a 350 later if you choose to pick that engine at some point.

 

also looking at the World S/R torquer 305 heads as a possibility. The car is a street car, is never going to see any track time and the mods are for my happiness. I do not have a high power goal by any means. With all the mods listed above I should very well be over 300 FWHP and that where I am looking to be