Hi Dunbar_58What is to stop you just using the MGA rack? Furthermore, a measly 38mm is only 19mm per side which you may get away with just winding in the trackrod ends as far as they will go, might have to chop a bit off the end of the steering arms and run a die up the arms to lengthen the thread. The actual type of rack itself won't affect the geometry, apart from toe out if it's too long!
Here's one I built earlier.
http://ca.photos.yahoo.com/grmtsunami
GavinR
