Double check ride height math
 

Here's the details:
Finished my rear suspension work on my 87 Targa, larger T-Bars, new bushings etc. After installing the larger T-Bars (30mm vs. 25mm) I set the spring plates at the same angle that I took them off. But now, the car is approximately one inch higher...probably due to the fact that the new T-Bars have a larger spring rate = less give.

The Bentley says that the smallest degree change by re-indexing the T-Bars is 0 degrees 10'. That will move the height approx 1.4 mm. There are roughly 25mm in an inch.

So to find the amount of spring plate angle change that will give me 1 inch less in ride height I...:

Divided 25mm by 1.4 = approx 18
18 X 0 degrees 10' = approx 3 degrees in spring plate change to achieve one inch in ride height.

Does this look right?

This may help.

http://www.vintagebus.com/cgi-bin/spring.cgi

Enjoy