Cylinder head advice

[65standard]

I have the stock 6.0 iron heads now. I don't know what number they are. I'm looking to build a high torque low RPM motor. My thinking is to use aluminum heads with smaller combustion chambers to raise the compression. Smaller valves and ports will be better to keep the velocity up in the lower RPMs. Aluminum will be better at reducing spark knock on a higher compression motor.

I have a 2005 aluminum head 5.3. I don't know what heads they are, but if they raise my compression to 10.5:1 or higher and the valves aren't too small, I'll use them. I'm also okay with buying any other set of heads that will be best for my high torque, low RPM motor.

Thanks for all the tips and info guys, much appreciated.