I have a Statesman mower made by MTD, model 699 that has a Briggs 20 hp opposed engine on it. Valve seat came out of the block and a head bolt broke and can't get it out. Is there a engine that will bolt back in place? so far the only option I have found is to buy a used block and reuse the rest of my parts, $150 for the block plus buying gaskets, rings or pistons, and etc.. Seen some new 17.5 hp engines for $519 which sound like a better choice but the shop said it won't work while another place said it would. Mower has a 46" deck and I wondered if losing the 2.5 hp would hurt that much. trying to do this cheaply as I really don't want to put much in a 11 year old mower ot buy a new one.