I am not sure about the subframe connectors. When I looked into them for my Mustang, I concluded that they would put me in a prepared class. The rule to look at is 16.1 G. I can't get it to copy to paste it here, but the link for the 2006 rules is
http://scca.com/_filelibrary/File/2006_solo_rules.pdf. There can't be any lateral members connecting the subframes.
I agree the rules can be very confusing. What you have to remember in interpreting them is that if the rules do not affirmatively permit a modification, then that modification is not permitted. It is not a matter of what is prohibited.
What frequently helps is getting people who have modded the same car to help. You can usually find this help on the SCCA Forums,
http://sccaforums.com/forums/. Try the classing board or the SM board.
No long ago I rode in a Mustang that Mark LaMaskin built with the full Griggs suspension. The handling compared to what I was used to from my '99 Cobra was just incredible. I am looking forward to seeing your car run with us.
Hope this helps.
David
[Edited on 11-6-2006 by wahoo5]