[6pack] Ride height question

[michael lunsford]

Last weekend I helped a friend install the Goodparts adjustable trailing arm brackets in an attempt to cure the ruptured duck look on the rear wheels of his TR 6.  When we removed  the Goodparts performance springs (I'm not sure what he calls them) I compared them to the stock ones and noticed that they were at least an inch shorter.  Even with the aluminum spacers he had been using, the negative camber (is that the right term) with these springs was way too much. He also complained about the harsh ride so we reinstalled the stock springs at the same time.
 
The newly installed stock stock springs ride considerably better than the "racing" springs which is logical and the ruptured duck look was remedied.  Since then he noticed that the wheel to fender height has eased considerably which is probably the way his 75 TR 6 looked when it was new.  
 
This brings up two questions, one is why was the effect of the Goodparts springs so great? and secondly, what caused the increase in height between the early 6s and the later sixes?  I know the increased height was due to government mandates.  Was this increased heightr accomplished by a change in the configuration of the trailing arms?  If so could replacing the late model trailing arms with those from an earlier ones reduce the ride height?  Also, how did they increase the front ride height?.
 
Mike Lunsford, 1970 TR 6