how much horsepower is gained from port matching heads and intake i have a 302 .030 over, if is not much, should i even pay the money to get it done

 

well it depends on the motor while you will notice improvement depending on your engine will be how much you notice it

 

+1 depends on the rest of the engine
Cam? Carby? Exhaust?

as a guide, if you want more power your best bet is improving the whole engine. More $ should mean more power!!
If you just do one thing like porting the heads or putting a bigger cam in or a big carby in isolation, you will usually be disappointed.

I bought a set of heads from a guy who had done just that and lost power and streetability by going too big for the rest of the engine. I dont understand the mechanics of why, but it just doesnt work!

I say leave it alone unless you are going to improve the whole package.

 

It wont be as good as getting better flowing heads, however you will feel a difference. I'm not sure about HP# gains.

 

You'll feel the difference. I wouldn't say it's worth tearing an engine down in order to do it though. And grinding on the heads with them on the block can be done, but adds a bit of risk with metal shavings getting wear you don't want them...kinda like sand when on a beach.