I defer to the experts on BBC/BBF, but to me it does not sound like you have anything that is near catastrophic failure. If it was mine I would run it for another month, and then plan to pull the heads off in October for a complete valve job with new springs. Then you can look at the cylinder bores and piston tops to help you decide on the rest of the engine, and if you want to pull it to go through the block, too. Just my thoughts...