[jams]

The best thing to do is setup your ride height (Assuming you have tires/rims) even if you have to have to use jacks and/or blocks. Once your ride height is known all you need to do is measure from the lower mounting point to the top mounting point and the guys at QA1 will be able to set you up with the proper shock.

I don't know if this will help your situation but Summit has a Mustang II conversion kit for the front. It costs 369.00 and I believe it comes with everything you need. Once I get a few more bucks I am going to spring for the new springs.