I have never had a problem with Heidt's products. One feature to look for is the use of OEM style upper inner control arm shafts in whatever front end you purchase. The OEM style are knurled where they contact the upper spring perch. I have seen Mustang II based front suspensions have problems holding alignment settings when smooth faced upper inner control arm shafts are used. They can slip, altering the alignment.
For what it's worth, I have never had a lower control arm problem when eliminating the strut rod either.