What's the best way to store a bare block that has not been machined yet?? I'm getting ready to buy a complete 400 for a future build, I'm not going to build it for a while but I want to completely tear it down so I can inspect the block and sell all the parts I'm not going to use. Should I just cover the cylinders with oil and bag it since it will need machining anyway?

We don't use a bag with a unmachined block, it seems to make it worse. I will use wheel bearing grease in the cyd and any machained surfaces. All my blocks are rust free..

I just tore into some longblocks that have sat for at least 15 years untouched in my MI polebarn. The cylinder walls didn't appear to get any worse than they were when put into storage. I just backed off the bolts that hold down the rocker rails when put into storage. How damp your barn gets may be another story, mine seems to get a lot of sunshine when we actually have it here.

To store a bare block.......I'd remove all the pistons and grease the cylinder walls up with wheelbearing grease as mentioned above. You can go indefinitely at that point. I'd leave the cam & lifters in the keep the lifter bores occupied with oiled up lifter bodies in there. The "fogger" cans of WD-40 sprayed over that is just cheap insurance.

What hurt my situation was the invasion of mice living in one longblock. Not good. The urine caused more rust than any humidity ever could.

There are a couple of good and inexpensive spray lubes you can use - both from CRC. One is Stor & Lube (or something like that) and sprays easily anywhere you want but the solvent evaporates to leave a nice sticky film. Won't rub off easily but does clean off very easily with solvent. The other is Wire Rope Lube and is very similar in that it sprays easily but the solvent evaporates to leave a greasy film.

I would spray the every machined surface and the whole inside of the block with either of these. Bag it with a handfull of mothballs to keep mice out.

Sprays are easier than trying to wipe down everything with a greasy rag!

I sprayed 1 block with motorcycle chain lube... its
what I had around and it did very good... it sat 3
years in a plastic bag