my '91 engine is stock as of now, but i will be adding a chip and cam sprocket soon. my first thought was to go with the dinan chip and sprocket since it is readily available. does anyone else offer a cam sprocket for the e34 3.6 - do i have any options? and is there any real performance difference in any of the many chips available, especially out here on the west coast with 91 octane gas? the only other mods to the engine i plan on is a supersprint cat back system. should i do the cam sprocket and exhaust first and then do the chip or does it matter? thanks!