Ok, maybe this will highlight my lack of experience, but I was working on the car and encountered this and it concerns me. I removed my water pump from my Cadillac flathead. Supprisingly, the bolts came out really easy. I took the pump off and realized that 3 of the 5 holes on the block were rusted out. There was a crap-load of rust all in there and 1 of the bolts had rusted in half the long way. Eventually, I will have the block worked over by a machine shop and I imagine they would be able to fix this, but I have no idea if its economical. If its not cheap (relatively speaking, of couse) or not possible to fix something like this, I would like to know now so I can get a new block. Anyway, I am attaching some pics. On a side note, I know why there is so much rust. I the wide shot, you can see the hose from the heater core with water still in it. The rest of the water in there must have leaked out or, more likely, evaporated out over the last 30-40 years since it was last started.
The head/head bolts seem good from the exterior, but I haven't take them off yet. I can turn the crank about 1/4 turn before it gets stuck, so it seems like its not rusted up on the inside.
Complete the teardown - it may have some other problems that can't be seen until the machine shop has baked or hot tanked the block. Hopefully, it hasn't frozen and cracked.
Just a thought, if that area rusted tht badly, what condition will the rest of the water jacket walls be in? Were it mine, I think I would be looking for another block. Gene
Take it and get it acid dipped. It will eat all the rust leaving a fresh block and it cost 40 bucks here. We do it on all the motors we build.