Hi everyone. I bought a 72 F250 Camper Special a few months ago with supposedly a 360 that had some problems with overheating and leaks. Well I pulled the motor out and found a .030 390, with a blown head gasket(water jacket to #1), cracked head in the combustion chamber (crack between valves and to spark plug hole on #3), two cracked exhaust manifolds. This is all easily fixed, but what I found when I cleaned the gunk off the block, crank and pan was different. The oil control rings were frozen in the pistons, but there is no ridge on the cylinders and the pistons are good. The block had suffered some kind of castostrophic failure in the past, as the block is welded in the skirt area and around the oil adapter mounting on the inside, the pan has been welded and the crank has scars on it. I dye checked the pan and it is ok. The crank looks ok also, I am worried about the block. The engine looks like it was rebuilt, bored .030, crank .010,.010 sometime in late 85 or 86 in San Diego area. I do not know how many miles the truck has been since then. Do I need to worry about this block or should I replace it? I know it has been a few years since the welds were made, but I really hate doing jobs twice. My confidence level here is hazy, anybody have experience with this sort of repair? I have already got another set of heads and had them redone with hardened exhaust seats, as well as another set of manifolds.
Thanks
JWRBoss302
72 F250 CS 390 4spd

 

I don't know why someone spent so much time and money repairing that block. Who know what else is wrong with it like a crack they missed. Any 360/390 block will work, if it were me I'd find another good block. Do you know for sure if the crank is a 390?

Barry

 

Yes its definitely a 390 crank, rods and pistons. it is a 67 block. One other note, is that after punching the freeze plugs out, there is some sediment in the bottom of the water jacket, black dirt it looks like, could this block been a boat?????

 

It's normal to accumulate crud and sediment in the bottom of the water jackets. The blown head gasket didn't help and I bet some oil was getting in too. Boat motors usually have tons of rust and scale in the jackets.

barry

 

There is some scale and rust in the bottom of the water jacket, not alot but some, in between the cylinders at the bottom. If someone put in some sealer in the cooling system, is there evidence of this that can be seen, color, goo etc???

 

I've never used a block sealer and don't know what it would look like inside, sorry.

Barry