CFF132797 is part of the VIN of the vehicle that the motor came in originally.
The suffix number will have to be de-nuded of paint completely to see the letters correctly. I tried every possible combination using A through Z instead of F. No dice.
At the driver's side rear of the block, there is a casting number. It is just ahead of the connection where the bellhousing matches up with the engine block and is shown as raised numbers on the block itself. Sometimes you have to get in there with a toothbrush and solvent to clean out the crud, then use a mechanic's mirror and a strong flashlight to see the numbers. Start at the firewall and go straight down.
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