What is the special n Schrick camshaft kits?
The Schrick camshaft kits for Seat include each for your purposes the complete package of necessary components, which are completely compatible together. So you can, for example, be sure to get the right valve spring / plates for the right camshaft.
But likewise financially the complete kits are worthwhile, because they are priced lower than the sum of all the individual components. Please note that different manufacturing tolerances on cylinder heads always make a review of the free movement of all parts required!