A question for the HEAD DOCTOR

[valley firearms]

Hello all,

I have been cruisng this site for a while but haven't posted yet. To introduce myself, my name is Mike, have 1968 coupe and I live in Alaska. Hello everyone!
There have been a lot of posts reguarding aluminum heads and I have been using the search engine to gather info. My problem is, I bought the car several years ago and don't know what pistons I have. I know the engine was rebuilt several thousand miles before I bought it. The miles are still low since I have been working on the car since and probably not have driven it more than 100 miles since the purchase. I'm sure the guy used standard flat top pistons. So, I don't know the C/R. A little background of what I have:

302 bored 40 over (307.65)
Holley Street Avenger 575
Edelbrock Performer
Pertronix Module
MSD 6A
Shorty headers
Comp Cams FS 280H-10 .512 lift 230 duration

This spring I will be installing a toploader 4 spreed w/hydraulic clutch.
I also plan on having a 9" built with 410 or lower gears . With that said, I have been pouring over information about aluminum heads. I have learned a lot in the last few days and I am glad I didn't go out and buy the biggest heads out there(like I wanted to several days ago). Just to give you the difference of my thoughts from several days ago, here is what I have learned. I was going to buy ProComp heads with 2.02 intake and 160 exhaust. I have read that the 2.02 valves with hit my pistons if they are not fly cut. But I have noticed some of these people advertising on e-bay say that there might be a problem with valve/piston clearance. Are they just trying to sell them by being vague? Now I am wanting the AFR with 190 / 160. I'm not sure about the intake runner size. A lot of heads are advertising 190cc. Is that the size/volume of the intake port? I figured with the 190 valves I'd be safe. Now there is the roller rockers. 1.6 or 1.7's? Will the 1.7's give me the piston slap I am trying to avoid? I'd like the 1.7 for more lift. Also there is the rail type rockers. Which is better, standard stud type or rail type. Is the rail type year specific? Can I use them? I have read they are non adjustable( only with shims). I am out to gain the most horsepower like every other guy so any help would be appreciated. If I have missed something please feel free to educate me. I want to buy the heads next week.