I HAVE FOR YOUR CONSIDERATION AN ORIGINAL PISTON AND ROD FOR AN ASSOCIATED 1 3/4HP HIT MISS GAS ENGINE. THE BORE IS 3 3/4 THIS WOULD BE CORRECT FOR HOPPER COOLED OR AIR COOLED MODELS. THE CHORE BOY, HIRED HAND AND HIRED MAN TO NAME A FEW. THIS CAME OFF OF A RUNNING ENGINE. WE WILL TRY OUR BEST TO GIVE YOU AN ACCURATE AND HONEST DESCRIPTION OF THE ITEMS LISTING THE GOODS AND THE BAD’S. LET THE PICTURES PROVIDED BE YOUR GUIDE. PLEASE VIEW OUR ITEMS OFTEN SINCE WE WILL BE LISTING MORE HIT MISS GAS ENGINE PARTS AND ENGINES THROUGHOUT THE YEAR.