In 1972, there was a 350SL that made it to the United states (4.5 engine). Here's the link where I got my information: http://fly.hiwaay.net/~gbf/107/rt.html
According to this article, the car was renamed 450SL in 1974 and horsepower was reduced to 190. In 1975, it got cats and power was down to 180. The 350SL 4.5 had 230HP and a 3-speed automatic. I'd love to have a 560SL(I've never owned a convertible) in the near future but I'll probably save up for a used SL600. They are both geat cars and I don't think anyone could go wrong with either.

Jesse
98 C43
94 Range Rover