These cars are built to rev. There torque and horsepower a way up in the revs. Some owners replace the rear ratios with higher gears to satisfy the American V8 lumbering hog low reving engine syndrome. However you end up driving below the desired power band and end up with a well thought out car sluggish and doing the opposite of it's design. My 66' 230SL has the stock 4.08 and it is just music to my ears, an engine running contently at 4000 RPM down the highway. The engineers were way ahead of there time with the small cubic inch high reving engine. Todays engines rev no problem, some way over 10,000 RPM. Look at the maximum torque on an engine and you can see where it should be running. I believe the M127 developes it's max torque at about 5000 RPM and max Horespower at 5500RPM. These engines love to rev when they are not worn out. Keep driving and you will learn to love the high rpm's and feel the power band. Remember though, as with any engine, it must be in good condition and warmed up to rev.
