several years ago i parted out ax 58 big truck,i think it was a 500 series?,it had a engine that looked like your picture,dimpled valve covers and all,it was a 331 that ran,i sold it for $800 and should have got a lot more,however i sold the bell ,flywheel and clutch separately for the cheap price of $200
edit!,it was a 315 not a 331