Hi all, new to forum hoping for some advice. I recently purchased 2010 zts 6000 with a broken connecting rod. After removing motor and disassembly I found a couple of cracks in the block up high enough that it still held oil. The Model number is 331877 B147 B1 and is a 21hp B&S platinum. My question is can I use any block with just the first 6 numbers or does code have to match the entire sequence? Also, will a 19 or 20 horse with first 6 digits also work with original piston? Any help is greatly appreciated.