I did it on a 250SE engine. There are several pieces that are different with these manifolds and you need all of them to make it work. The rod above the starter is longer, the aluminium side cover on your engine is replaced with a flat steel disc and the length of the rod going through the heat shield is possibly longer. There is also a small bracket that holds the bell crank and a pair of screws that you need to mount it on to the steel disc. The heat shield is also different and you will need different front pipes for your exhaust system.
You will see a difference in performance.