I'm glad you called them a gas pressure shock absorber. I've never had a choice of valving. Do you have to make a special factory order? In about 1973 I bought some Bilsteins 2nd hand that had done a few seasons on Chris Heyers Catalina Rallycross Beetle. I put them on my Beetle rally car for a few years then transferred them to my 1500 Beetle. After about 250,000kms on the 1500 I noticed a knocking sound in the shock. I removed them and there was about 2mm end play in the shaft as if the piston nut had come loose. The shock absorbers still worked perfectly. For rough road or off road use use I would go Bilstein. For on road I would use Bilstein or Koni.