diddy you are right, the part number is cr11747 and i got them from summit racing which is only 23 miles from where i live and i just checked and they are $195 and they were 7/16 stud.. I cant remember the web site that i got my pistons from but i use to belong to and amc forum and i got the web site from there, I will do some checking and find out the website and post it later to nite.