I had heard rumor that muscle motors closed too, but I just tried number and got recording as if still open for business.

I got a Killer Krate small block from them after researching a lot and finding they have good reputation, and the engine is very stout!

As far as warranty is concerned, unless company is right around the corner, the warranty is meaningless to me. You are going to have to go thru the trouble and expense of removing engine, crating and shipping back to builder, then they are going to inspect it and determine if it's their responsibility or your blame, and who knows what they'll come up with, and then you'll have to wait to have it shipped back, and reinstall. Even if they cover the repair, you're stuck with at least one way shipping, removal, hassle, and all the down time. I'd be repairing myself before I went thru a warranty claim, again, unless the builder is where I can get right in his face.