Here is another write up/DIY on swopping your e30 rack with an e36 rack. The best write up I have seen on the web. They use a rack swop kit also available on e30tech site, but I think one fasion your own spacers as Im planning to do myself. http://www.e30tech.com/forum/showthread.php?t=21391
Hope this helps
nice write up though, great with the measurements.