Hi my M50 has 176k on it and is starting to feel a little rough. It burns no oil. But I was thinking is it worth it to convert from a non-vanos to a vanos, if I do a rebuild? Does anyone have a parts cd handy? Can you tell me what parts are different between the engines? Are the blocks and the pistons the same? I think the head and the cams are different. I know the ecu is diferent. Please help me with this info. TIA b '91 525