My husband and I had a '65 Chrysler/Force 105hp outboard motor that was blown, so we bought a '73 Chrysler/Force 115hp powerhead to rebuild. Problem is, the 5/16 head bolts that we currently have are too small and 3/8 bolts are too big. If anyone has a manual, could you let me know what size bolt it calls for. Or, if anyone has any other suggestions I am all ears.