New 1958ish 392 blocks?

You're going to have to call them. There is nothing on their site about any 392 stuff...

Edit:
I just found these on craigslist...
https://sacramento.craigslist.org/pts/d/gardnerville-1957-chrysler-392-cu-in/7046039129.html
392 Hemi with 8-71 Mooneyham Blown 850 hp Pump Gas Motor

site:bearblockmotors.com 392
392 | Bear Block Motors

Bear Block Motors

Phone: 818-349-0999

Fax: 818-349-2999

Email: [email protected]

Address: 9315 Eton Avenue, Chatsworth, CA 91311