I posted this on yahoo a couple of months ago. This is what I was told by a mk2 owner (not a club member) He said they are the same height and diameter but they are stiffer and should result in a faster valve train.
I dont know if this is accurate. I am thinking of doing it.
The problem with stiffer valve springs is that it will add more drag to the valve train too...which will eat up horsepower. If your building a beast of a motor, then they may be neccasary, but IMO, its not needed on a stock or mildly modded motor.
Unless you are significantly raising your redline, and are concerned with valve float, higher spring rates not only consume more power, but also flatten cam lobes much more rapidly. Ask me how I know.:duh:
I guess I was asking more due to I was curious about replacement Valve springs from a chevy would be cheaper than trying to source some valve springs from a very old car thats not really supported anymore