You may want topop the freeze plugs and see what you have restincyting you if it is mud,sand or rust it needs to be looked at. Good luck.

454 mag, when I tore it down I got probably three double hand fulls of flaking rust and crud out of the block.

I pulled the circ pump and it is looks brand new. Coat hangered from the pump, down the block and from the drains up. I still got small pebbles/flakes size chunks of black rust to come out. It seems like most of its out, as water if flowing a bit better now.
It looks like it will would be easy to remove all but one of the freeze plugs, but there is very little room to put them back in, without lifting the engine. So i guess im gonna continue flushing and hoping for the best. Also found that the timing only had 4 degrees initial, so i bumped it to 8.
Haven had i back out yet so we will see.

I had a similar problem with a 454 in my 27 fever a few years back. After going through almost everything you did, I finally took it to a pro. Guess what? Raw water pump. I had rebuilt it but the body of the pump was worn, no longer elipticle, and rounded which created intermittent and low suction. I didn't see any mention of checking the body of the pump in the thread.

I replaced the impellor and the plastic housing that the impellor rides in and the hoses hook too. But i didnt replace the whole pump. Is that what your talking about? I Also just removed the raw water pump and looked inside to verify that all the blades were still on the the impellor and in good condition ( They were).

There is a product I think called rust away? Maybe that will help you get some of the crap out of there. I have also seen the water pump problem. Pumps are expensive however so you want to make sure it will fix the issue.

That is what I am talking about. Sound slike that is not an issue. If the impeller is still in good shape it apparently did not run dry.

Ok so i pulled the 45 degree fitting and surprise surprise, the rubber o-ring is almost pushed together. I can barley get a coat hanger though it. Now my question is......Can i just yank this o-ring out? Doest the drive have to be pulled to get to this? Is the o-ring just supposed to rest inside of there or is it recessed or something. Its very corroded and hard to tell what it "should" look like.
Thanks everyone for all your help. Seems im almost there
Ed

The part is actually a tapered and threaded plastic bushing. It requires a special tool to install and is sometimes quite a pain. Be sure and clean the aluminum housing around the OD of the hose. The drive side is also a suspect area (same type bushing). Never a bad idea to replace the hose when everything is apart.

So your saying i can remove the inner bushing without pulling the drive? I know i should check the one at the end of the hose but im just trying to get this thing moving, as valuable boating time is being lost. BTW.....where can i get this tool and whats it called.
Thanks
Ed