SBM DOWEL PINS HEADS TO BLOCK

WANTED: Smallblock cylinder head to block dowel pins shipped to zip 48036 Michigan! Seems everything available is 1/4inch where clearly these are larger, maybe 3/8 or even 7/16. Any help would be appreciated!
Are you looking for new only, or would used be ok? I have a junk 360 block I cut a rear mounting ear out of for someone so it’s going to be scrapped anyways.