5.7 runs on muffs, not on the water.
#11
Registered
#14
A friend of mine had the same issue with a SBC..it would start and run good on the hose..back it in the water and nothing..pull it up and it would start..turned out to be the cam..he didnt have thru hull exhaust and wanted it so he added that instead of changing the cam..(per the advice of someone else)..I think they said it had something to do with back pressure????..I'm really not sure..but the thru hull exhaust fixed it..I hope this is some help..