i have 2 in the crate virgin buick stage 1 blocks the casting #'s are 25500004 then a large #5/6 on both-i was told these were prototype blocks -does ne one know? they are in the factory cosmiline the are WAY thicker that the 009 blocks and have splayed caps w/them i want to sell one but need 2 know what it is first! you can see a pic of it @ www.ryanfoxmosley.com any help appreiciated!!!!!!!!!