Ah crap, I might be screwed

[jkh04200]

Help me with this please.
I was changing the plugs, 305 Chevy 228, I/O, water ran out of the #8 plugh hole. I had no problems witrh it last year. I have had the outdrive off of the boat for several months. Replacing seals and bearings in it. Any way I have started the boat 4-5 times over the past 6 mos without any water. I didn't let it run but just a few seconds so I never let it get hot. And since I did'nt have water hooked up to it that would eleminate reversion. Right? So where is the water comin from. I'm leaning towards the manifolds. They are original and I never drained them this winter. So they still have water in them.
If it is the manifold couldnt I pressure up that cyliner and hear air coming out of the exhaust tips??????

[502 JET]

If you did not run antifreeze through your motor you may need more than manifolds.If the manifolds are old the may of rusted through.You can remove the manifold and riser make a plate to cover the riser holes and pressure test the manifold.I have seen blocks ruined because people thought they got all the water out but the block drain holes were plugged with rust and sediment.Cast iron manifolds are consumable parts that will eventually go bad.

[jkh04200]

Thanks for the response. I assume your talking about a crack due to freezing this past winter. Thats definatley not it. I'm in Houston. We don't have those kinds of winters. If It does drop down below freezing, I'll put a drop light under the engine cowling. That low temp only last a day or two around here.