water got in the motor and ruined it. no bad gaskets,block not cracked, heads not cracked. who test exhaust manifolds & elbows for leaks. or how do i do it my self.

best place to pressure test your manifolds and risers is by the people who built them, most will test them for free, but it will cost you shipping, a small price to pay if you look at the worst outcome[engine failure]

if they are stock the cast iron is probably porous time for new ones. I f not make a plate to cover the hole get some hose capsone with an air fitting and fill with soapy water and pressurize