The first time I started my engine with new Hardin tips with internal flaps I thought the motor was coming apart. If that was the first I ever started the motor I would've started tearing heads off, lol. Just rubber flaps to boot.

Some of my lifters bled down over the winter it took a good five minutes of running and a few blips of the throttle to get them to shut up.

So i go to pull manifold off and there is rust in the 2 or 3 back cylinders on the port side. Got valve cover off and yay a bent pushrod! Have no idea where to go from here.

Now check for a bent Rod to match

Doesn't sound to good. I'd pull the engine before you get to far into it. Bent pushrod isn't real common unless there is something that caused it. You might end up with a bent valve also. You didn't suck anything through the carb did you? Flame aresstor stud or nut? I've seen them bend from excessive play from collapsed lifter and or wiped out cam lobe. Or from broken rocker arm stud in which case pushrod slaps up and down causing it to bend.

Now your water or reversion issue. Whole new problem. With what you have going on I'd start pulling now rather than having this that and the other thing all over in the bilge etc. you've got some investigating ahead. Keep us posted.

Ck exhaust manifold ports ports just to see if you did spit something through the engine. Not just the cylinder with bent pishrod as its very common to transfer around to other ports through intake.

if the piston made contact with the exhaust valve it can easily suck water in on the intake stroke.don,t ask me how i know that but i have first hand info on that.

Took the words right out of my mouth. Alot of times this goes hand in hand.

I'm assuming you made no other changes correct? No cam change or heads milled? Piston to valve clearance? Also ck your installed spring height on the problem one compared to a couple others. Ck Underside of spring retainer to top of valve guide clearance. It takes a lot to bend a pushrod so there is definitely a concern but not the end of the world. Stock rockers or roller rockers? Inspect very carefully. Maybe swap out with another pushrod just to roll engine over by hand and look over very closely and also keep an eye on the mating valve. Remove spring if your able and see if you can rotate valve as well as up and down what your able to. Make sure and keep some air pressure through your spark plug hole. I'd be surprised if you didn't have a bent valve. With your water or reversion issue is it possible it hydrolock that bent the pushrod? A rod though??? Possible but.... Either way looks like your in for the long haul and find out soon enough.

I didn't recall if engine was stock or not so just throwing these out there anyway.

i have seen rods get bent from hydraulicing a cylinder but i have not seen that bend a pushrod but i guess it could happen.

Maybe the lifter collapsed and jumped off the rocker