Hardin marine seaward manifolds
 

Does anyone else have these manifolds. If so how do you change the spark plugs in your motor? I put a socket on the plug and within a half a turn the socket is hitting the manifold. Any help would be great.

Never dealt with those manifolds, but The older Mercruiser manifolds did this too with typical spark plug sockets. I had, in my tool collection, a few thinwall 5/8 sparkplug sockets that fit.