I will post these here and see if any of the guys on here who are engine masters can tell me what these fit. I think the 1 on the left with the spacers are small block. the one in the middle is small block and the one on the right is big block. I don't really know because they have been in the shed for a long time and I need to move them. the one in the center and left measure just over 19" and the one on the right is about 20". can I get some help here. Bill