Rico above told you what the number in the pic indicates, plus that overstamped 9453 would indicate to me the engine has been rebuilt, that'd be the rebuilders ID
the casting number you want can't be seen from under the truck, it's on top of the rear flange the bellhouse mounts to on the drivers side - you need to use a mirror against the firewall to look down at it, easy enough to get in there with a brush to clean it enough to read
Bill
