My brother just had his timing belt break on his 88 325is. He will be taking the car to some NASA driving schools next year, so he wants to make some improvements to the head while we are repairing the damage caused by the busted timing belt. I suggested that he throw in a performance cam, but really didn't know which cam to recommend. I've seen 272 and 288 cams available, are there others? what would be best for a car that will be street driven 95% of the time? When upgrading a cam in a M20 engine, can stock valves, rocker arms and spring be used? Is there enough performance gain to make it worth while? While we have the engine apart, we will be sending the head out for machine work and have it perterd to match the manifolds.

What exactly does 272 or 288 duration mean?

Thanks for the info.