Jack Deryke and engines

Depending on what was done to get this aengine into your Pantera, it might be as easy as unbolting the thing and bolting in any 351-C. It occurs to me that a VERY few M-series engines had both big-block and small-block bolt patterns drilled into the rear of the blocks, so there may not even be an adapter plate to the ZF. Too, the motor mounts may simply have had a different pattern drilled into them, or the top half may have been somehow altered for the big-block pattern. Too many variable to make more than a rough guess without a few photos to sort out details. Do you even know if the M block has 2V or 4-V heads? A third choice that means tearing down the engine, is closed chamber 4V heads.All incidently, fit the Windsor block with some work. What area do you reside in?- this car needs someone very familiar with the Pantera to tell you exactly what you have there.