IMG_2445_zpsbecfeffa.mp4 Video by NEB15 | Photobucket
4.3 vortec. just a week back from top end rebuild and it dies going up a large hill outside town. symptoms; going up the hill was a sudden loss of power, was really hot when it got to top (but not boil over), spudderd out as soon as i let off gas, no CEL, no fluid loss, oil is bit burnt. after it cooled it starts right up. same noise in or out of gear, same noise with fan belt taken off. Ive heard a few theorys (crank bearing, cam bearing, flywheel, rod, piston seal) and would like bf's thoughts. my mechanic needs a few days before he can bring it in and do diagnosis starting with compression (was great after head work)
Any ideas? anything i can do in my driveway to locate the source?
edit: ran with a scanner and no misfire either

 

U got my vote for a rod bearing!!! My original motor had same noise not as loud right before it tossed a rod through the block!!