The early 500SE/SEL's were indeed very fast. I rode shotgun in a '81 500 SEC in '84 heading west from Munich to Stuggart and we easily cruised at an indicated 250 kph. The owner said at the time that his car was produced before MB changed the rear axle ratio. From my technical data book I note that the ratio was changed in Sept. '81 from 2.82 to 2.24, a very meaningful difference. While the earlier car would pull redline in top gear the later one would not. We owned a Euro 500SEL that was produced in 1982 that my wife drove as a replacement for a very rusty Euro 450SEL. She frequently complained to me that the 450 was much quicker than her 500 was and peladed with me to resurrect the 450 (she was a very fast driver). Also, keep in mind that the later 500SE/SEL had a taller rear axle ratio than the 560SE/SEL did (2.47). In short, I believe that egutie's 500 could run 155 before the shop work. One question for egutie, was the front cover removed to replace chain rail guides? If so, did they mistime one or more camshafts and/or ignition timing (Euro ignition timing is 16 deg. +/- 3 BTDC with vacuum connected at idle)? Mark