I have south side machine sub frame connectors. They weld in place and have stiffiend the car up considerably. They do occasionally bump the terry houston dp I have installed. When we installed mine I didn't get them as close to the floorpan as I should have. This left less clearance for the downpipe. You will need to remove the seats and pull the carpet back in the areas you weld them at. At this point I have two potins , Either modify the pass. sub frame connecor in the front or the Downpipe. I am probably going to modify the sub frame connector. I feel the downpipe should have been 1/2 - 1" shorter between the trans elbow (on dp) and the elbow at the subframe connector. One guy I seen on this board has cut the dp in this spot and shortened it 3/4" and rewelded it back together. This solved the rubbing problem. Personally I'd rather modify the frame connector, then cut my $500+ down pipe. My dp also ocassionally bumps on the pass. rear bottom a-arm bracket, I have been told to dimple the pipe there. The sub frame connectors are available from Summit Racing. The Phone # is 1-800-230-3030. Since you didn't install any connectors yet, if you get the same ones I have, you could modify them before you weld them in. I searched around and checked for a couple months before I got mine and south side had the best connectors in my opinion.
Wes,if your interested in South Side connectors,I have an extra set for sale sittin in my basement.I ended up with 3 sets,installed one,sold one,and still have this one.
I heard the GW will fit but I feel theyre flimsy.I personally like rectangular tubing over round tubing for rigidity.
What I did on my install was to shorten my THDP rite at the bottom so additional clearance could be gained.There is a seam there already and it involves someone with a tig/cutter to do it.No rubbing probs here and the SSM SF's were installed unmolested.