Bummer........that rack could probably go down by cutting off the brackets and "adjusting" them down. Did that with mine but moved it up. My pan is different that the Charlie's one you have.....I am gonna get a pic of it to see
That's a big whack out of the motor mount to get that manifold (header) in there. It still looks like it will do the trick.
Added pic....my pan looks a lot shallower than the Charlie's one.
http://www.weldtechstainless.com/