I have just purchased myself a 1970 Mach1 351v4. I have worked out that the engine is a cleveland. Can anybody tell me how I can work out if the engine is the original block fitted by the factory.

 

casting numbers....check on the intake manifold or behind the starter on the block....it could be differnt though as i have a 302.......windsor block.....not a cleveland so i dono.....google where to look up the casting numbers for the clevelands.

 

Other than date coding the block to see if it was cast just previous to the build date on the car, I don't believe the blocks were stamped with any specific number corresponding it with a specific body. Generall speaking, if the date code is within the 2-3 months preceeding the build date of the car, it can be considered an original block. Hope this helps.