Vee_Que;8720 wroteSo the answer then is I need to buy some new ones? Ok.
Not necessarily, just re-explaining what the process typically is.
If using used springs, the preferred process would be -
1/ Measure ride height with springs fitted to car - wheel centre to guard lip
2/ Measure free length of each spring
3/ Measure rate - spring dyno
Springs need to be marked left & right to account for wear and tear and we require accurate numbers for the above. Only then will we have a good, known, starting point.
Anyone who has bought our DVS spec 240 springs will note that they're marked left and right.
The reason for this is that the RH spring really isn't quite 250lbs - instead, Its nearly 255lbs. This offsets driver weight as most people do their 'spirited' driving alone and we look at these springs as suitable for entry-level track work.
We've sent a few sets overseas and simply suggest that the spring marked RH goes in the left side of the car and vice versa for LHD markets.