Just
Took
The other manifold off and there is also water inside the manifold and the exhaust
Ports on the head are wet

would be better to start the motor, even with no manifolds at all. run about 30 seconds. will blow out all the water (on the top of pistons) and the heat will dry out the little left. drain and replace the oil also. if water in oil, might take 5 oil changes to get it all out...another possibility. this is a big block. i am assuming raw water cooling, not antifreeze and a heat exchanger. salt water? or fresh? the valve guides rot out and pass water direct into exhaust passages.

do not attempt to start the engine,as stated in an earlier post,the cylinders may be full of water,you don,t want to hydraulic the engine,pull the plugs and turn engine over by hand,use a long ratchet and a 3/4 socket on the harmonic balancer bolt.if you found water in some of the exhaust ports,id bet some got in some cylinders.

I've already cracked it up and it starts just fine, you think the valve guides might be rot? They only had around 1 hour of use since the rebuild

I had a friend with an old woods truck with no manifolds on it and he started it and the noise and fire shooting out of the heads put me to my knees I was laughing so hard (with my ears plugged), I can only picture it in an engine compartment!!

Get a set of manifolds and be done with it

Am doing a compression test tomorrow to seehow things are

Just did the compression test and every cylinder was at 118-120, I did had water in the spark plug of cylinder 1

I'd pressure test the manifolds for confirmation. To do that plumb city water to an inlet nipple, plug any outlet ports. Then turn on the water and watch for water to appear in the exhaust gas section of the manifold. It will be obvious if they are leakers.

plug all the water ports, leave one to install a guage and a shrader valve like on a tire you can add water to the manifold just a little so you can see water pressureize with air and watch the guage with air pressure a leak is more to show up because the heat expands any crack while the engine is running, good luck had the same problem with a set it was spraying water on the exhaust valve and bending it only way i found it was with air pressure aprox 13 lbs should do it.....