Here's some link's to the Standard Abrasives Motor Sports Division, it was posted on the old board by someone else before, they have supplies you can use to clean up the ports on your heads and DIY instructions on how to do it, also they have DIY instructions for cleaning up your block, crank, rods, and pistons.
http://www.sa-motorsports.com/products.shtm
http://www.sa-motorsports.com/diyport.shtm
http://www.sa-motorsports.com/blockdiy/blkdiy.shtm