Hello,
If you do have to switch engines, be sure to use a 280SE (fuel injected) engine from a six cyl. W108 chassis. They are vertually the same. Some minor plumbing differences and the SL has a mechanical tach. drive The important thing is to keep all the original engine parts so the next owner can re-build it and switch back if he likes. With this in mind, as long as the car runs well, is kept fairly original and restored well, the value should not be decreased too much for a nice driver. If the car is restored to show or higher standards, the poitential value could be hurt a bit more with the sedan engine.
