I'm in the process of rebuilding my 302 and trying to figure how I want to set this thing up. For a bad *** street rod would you go with the 165s or 185s. Also how much more hp is typically seen by going with the larger displacement 30-40 hp?

 

The market for AFR 165s is for stock shortblock cars where piston to valve clearance is a concern. If you're rebuilding, any aftermarket piston will allow the AFR 185s to be ran with a good selection of cams. With any AFR headed car, you better be greater than 1rwhp per cubic inch (or else you need to look in outside advice on your combo). So increasing 25ci from a 306 to 331 should net you a minimum of 25-30rwhp. With a good, high attention to detail combo it shouldn't be difficult to manage 40+rwhp more.