Complex sentence: This combination yielded the horsepower potential of the 351C with the ruggedness of the 351W small block and was possible because more 351C 2V cylinder heads were manufactured than the corresponding engine blocks (the 351M and 400 used the same head as the 351C 2V).
Split into simpler sentences: This combination yielded the horsepower potential of the 351C with the ruggedness of the 351W small block. This was possible because more 351C 2V cylinder heads were made than corresponding engine blocks (the 351M and 400 used the same head as the 351C 2V).