coal miner - I believe youre referring to the 1J0 511 115 AN and
1J0 411 105 CD spring part numbers which are 5 and 4 green dots. These I believe can be swapped to the mkIV jettas.
Nevada - doing research seems the CT is the heavy duty springs and the BL is the towing springs. The CT being more stiff. Ive found the CT springs from $125-200 shipped. Where as the BL at approx $90-125.
bl - Rating 611-645 Kg - 363mm tall
CT- 211.5 lb-in and 381mm tall
The rating for the kg spring is odd from what i found should be kg/mm which converted to lb-in would be 6.11-6.45 im assuming and that is approx 350lb/in
If any one can confirm all this information that would be great.