thanks for the info guys. I cant remember what the casting number was but I know they have the 1.84" intake valves. They are in stock form and the only work to them has been a valve grind. They didn't need to be milled. I do plan on using flat pistons but thats only because I have a set lying around. The cam I have requires at least 9:5.1 compression and is a Summit Racing SUM-1106. I only plan to use these because they came with another project I bought off a guy and the engine he gave me was a 400 so they wouldn't work. I'm sure I'll be told to use something else lol. Let me know guys