engine help.

[Stephen717]

So I fell into a bit of luck today. I have been trying to get stuff together to rebuild a 350 from a 1992 silverado and have been trying to sell off the swirl port heads and intake since I got it. so there's a guy at the end of the road I live on that has been working on motors for years and has lived above me for about 3 years now. I asked him if he would be willing to buy them and he said that he had doubles of everything but needed a solid crank. I took him the one I had out of the motor I have been trying to research and get parts for and he told me that the block is useless (it's a cast # 727 block from a truck. He said that I would be lucky to make 240 hp with it.) but he liked the crank I brought him. It just needed cleaned up. so long story short he traded me a 350 block from a 1988 corvette that is already set up for a roller rocker setup. He told me that with the swirl port heads I could make 300 hp on this motor pretty much stock. But I am trying to make 500 to 550 hp with this thing. I already know that I want to get it punched .20 over and I would like to go with the roller rocker setup. but other than that I am very inexperienced with motors. Will an older set of heads and an older intake fit on this motor? what cam and crank should I go with? What pistons should I use? like I said I would like to make somewhere in the ballpark of 500 to 550 hp. I know that the numbers on the block are GM 5.7 LG, J267, 62, 638, 1493638, H, V1029ZMD, 1J5106238, 627, G1, but That's about all I know about it. any help would be greatly appreciated.

Thanks,
Stephen