I am looking to perform an engine swap from a 1976 450SLC to a 1980 450SL. I understand that the 80 has a 4 speed transmission, which I would prefer over the 3 speed from the 76. In doing the swap, is there anything special that must be done to make the engine/transmission compatible? Are the engine mounts the same placement? Any advice to make this happen would be great, if there is anything!

Thank you!