I bought this car from my son in law who hadn't done anything with it after parking it 25 years ago. He thought that all it needed was a fuel pump. WELL....after exhausting all of the normal tricks to get a seized motor to roll over (Marvel Mystery Oil, Diesel fuel, JB Blaster, etc.) I tore the engine down and had to drive out each piston using a large hammer and block of wood. After givin the block a bath we found cracks. Two 3" long cracks above the lifter bores (one on each side of the block) and a 6" long 'L' shaped crack that ran through the middle of the center freeze plug. I'm sure glad the freeze plugs did their job. I appears to all be repairable. Since it is the original block I'm considering my options. The big question...Is it worth the added expense to save the block since it's the numbers matching block???? What do you guys think???

 

How much will it cost to repair?

Freeze plugs are not really there to prevent block cracking. The are to seal up holes which are left over from the casting process. Calling them freeze plugs is a misnomer.

 

If the car is a very nice car and is low production and you are into the numbers matching thing. Then I say go for it.

But if it is going to be a nice car and a driver, put a 455 in it. Everything from the 400 will bolt onto the 455. Find a short block 455 and put it together from the 400.

You might want to save the 400 block for the future, but if it has cracks in the lifter galley, there might not last all that long. JMO.

Gene

 

Find another 400 if you want one that bad. Don't try to fix junk.

Or......put a 455 in it and put the junk in the corner

 

Hello Jawsmon,
I tend to agree with the others. I would find another motor. Unless it's a really special car, when I go to sell one with the numbers matching, nobody cares. It's only if they think it's not matching, they pretend to care and try to talk you down. Get the best deal you can on an appropriate engine, and kiss the other goodbye.
Just one more man's opinion.