454 chevy engine

[fritzer]

I have a 24 ft baja with a 454 chevy engine. Under a load at high speed it misses. Before all this had happened the water pick up pump impeller went out causing the engine to overheat. Can anybody out there help me with my problem?

Thanks

[CDK]

Overheating a gas engine initiates a sequence of events, from burning away the electrodes in the spark plugs to complete destruction of the engine. How much damage there is, depends on the elapsed time between the pump failure and the helmsman noticing that something isn't quite right.
If your Chevy is raw water cooled and the overheating was serious, lots of debris have detached from the walls of the engine block; that may lead to partial or complete blockage in the central part of the block where water velocity is lower.

[TollyWally]

The first thing to do is check the ignition system, then the fuel system. I have a 454 in my boat. If it was me, I'd spend the $100.00 or so and replace plugs, wires, and dist. cap/rotor. Then I'd swap out the fuel filters and put a pint or two of dryer in the fuel. In the hour or so it takes to do that you will have by default examined your engine fairly carefully and may discover the other little gremlins that often go unnoticed, and your motor will be freshly tuned for summer.

[Capt-Ron]

Blown head gasket.
Do a compression check.

Capt-Ron