There are a few guys that do not care for magnum engines, they do take time to break in right but they are a beautiful running engine once broken in, just take the time it requires, then you will have one of the nicest engines out there, i have talked to many guys with magnum engines and they all seemed to take a bit longer to break in but once they have some time on them, you will be very happy with the engine specially the way they idle, so slow and even, and have nice power.