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


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics