shamusj

Hi Guys- I finally got around to tearing down a spare motor I had sitting around. I was hoping to rebuild and use it yet based on the cracks I'd say thats a no go.
I'm curious- is damage like this from a freeze expansion or from burning the motor up ? There was water/rust evidence in a few of the cylinders and a fair amount of sludge in the bottom of pan. Bearings looked a little dark yet not spun.
Motor wouldn't turn because #4 cylinder was out of shape- I worked all the rods and pistons out and the crank turned easily.
I'd like to use the heads and intake manifold in the future- if someone over heated the hell out of this motor- I'm concerned these parts might be trashed.
If memory serves- I can use the crank of this '68 400 in a 455 block- please correct me if I'm wrong.
Thanks

oldcutlass

Usually that's from expansion due to freezing water in the block.

joe_padavano

That's from freezing. Ironically, the original G-block in my 69 442 has a similar crack in the cooling jacket, right behind the starter. The 68-69 400 crank is the same part number as the 455 crank.

wr1970

Might be possible to weld crack if there is no cracking in cylinders.Must be in water jacket only.

shamusj

Thanks gentlemen.
I considered trying to have the block repaired yet 6 visible cracks probably means theres more damage I can't see. A 455 block is easy enough to find.

Question- are the bearing caps worth saving? Not sure if they are junk or useable on another motor. It's a pity- this motor was a virgin- never opened up, never monkeyed with....until I came along.

wr1970

Cost of trying to use those caps not worth it.I agree 455 is the way to go.