I have been all over that area and can't see it, is there a chance the VIN for that block code is stamped in a different area? I just got the car a month ago from out of state and was told it had a 68 block, I had planned to replace the current powerglide out with a TH400 this winter and have the engine pulled and detailed. I am going to try and pick up a correct block and change it out if things work out.