4 Wheel alignment on a SPF?

[JCoop]

I just did a 4 wheel alignment today using my friend Joe's Hunter computerized equipment at his shop. We set it to 26.875" ride height all around, then factory specs on alignment. We couldn't figure out how to adjust castor; looked like there was no provision for adjustability. Also, the rear wheel camber had to be adjusted by taking off the wheel and disassembling the heim end joint at the top, turning it in or out, locking it up, reinstalling the wheel, then install the Hunter sensors again and re-checking. It took us 4 hours to do it right. In the end, after doing toe in .125 F & B, Camber -.25 F & B, castor fell in at +4.9", which was within spec. I had wanted 2" as steering is heavy on my car with the BB in it. Starting specs were way off and the test drive confirmed it. Rides and handles like a dream. So, $400 for a proper alignment isn't unreasonable. So anyone have a hint on how to adjust castor in the SPF?
PS. Warren, the $60-$80 alignment fee you pay over there is an absolute bargain!