Has anyone come across a 22R timing cover/water pump that uses a 6mm bolt for the hole closest to the pump shaft? Every 22R pump I've seen has all 4mm bolts except the long bolt that helps secure the cover to the block. This is from a 91 pickup I recently got for super cheap because son of previous owner didn't bother to change oil. The timing cover is stamped Toyota Aisin and the water pump is too.