LA 318 advice

Nope. Not all head bolt holes are blind. This has been hashed out here before many times. I've seen both myself. Blind holes and bolt holes open to the water jacket. Others have here as well.

Everything up to the mid 1980’s has blind holes.

All 340’s and 273’s have blind head bolts.

The 1985 virgin I just took apart yesterday has blind head bolts.

I wouldn’t use a block that doesn’t have blind bolt holes.