looking to find specs on 340-X heads.

well they cam with the 360 I bought for 350.00. I think I got a good considering they look like they had never been re-done.

If it was me I'd at least make them show me the cracks so you know your not getting ripped off. The X heads are valuable peices today for guys looking for original parts for restoration and their are crooks out there that might say their cracked just to make a buck.