Can you get around the valve covers by using an offset, segmented shaft? There are tons of hot rod parts available that you should be able to adapt including u-joints and flanged support bearings. As long as you don't go beyond about 30 degrees on any segment, you should be OK.
That is exactly what I am having to do on mine.
Last edited by Tango; 12/16/2015 8:08 PM.