Many people have the misconception that all you do is put in a bigger cam to get more power. WRONG! The VW is extremely sensitive to cam changes. Care must be taken or you will end up with an engine that will not idle correctly or perhaps not at all. You could even end up with much less power than your stock engine provided. All higher performance camshafts are designed to reduce low end power and add top end. If improper combinations are chosen you will lose the low end and have no more improvement or little gain in the higher RPM. To maintain or improve the low end that has been lost other modifications are mandatory such as adding CCs to the engine with bigger bore and or a stroker crankshaft. For this reason a good general rule for street engines is to select the camshaft last. You must select ALL other components first and then the cam can be selected. The only exception to this rule is when the engine is for race use only.
There are some general rules you can rely on. First, the lift can usually be increased with little effect on the low end power. This will allow higher RPM provided the head will continue to flow at the higher lifts.
There is a diminishing area of gain with extra lift if proper head work is not performed. The more carburetion and head work, the more cam duration that can be used provided a correct balance of valve size, intake, and exhaust size is maintained. This balance is critical to both the functioning of the engine, tuning and running temperature.
The bore/stroke combination is also related to this area because the larger the engine the harder and faster it will suck through a specific port. So, often people get cams that seem to run fairly well. However, they had nothing to compare to, so they never knew whether a better combination could have given them more all around driveability throughout the RPM range for the same investment. This is one of the major reasons we recommend being clear about the combination you want as it allows both of us to look at the complete road map of the engine, results desired, budget and what will be produced. You must understand that asking for a cam recommendation without every possible fact creates further guess work on your part and we will only assist you with a cam selection at the time you are placing your cam order.
A good example of the importance of this was when I put a GB 297 cam in a 69 X 88 (1679cc) engine with single port heads and a Holley 300 CFM carb. It ran strong, but idled like a top fuel racer, rough and way too high. It jerked and bucked at a steady 35 MPH in 3rd gear around town. Miserable to drive in 3rd yet the RPM was too high for 2nd gear. I installed the dual Kadrons, and it was the difference between night and day. It still had a small amount of the rough idle, yet was fairly smooth to drive.
Next, I put on dual port heads and kept the Kadrons. Again, even smoother, with only a small amount of rough idle. Then the GB 479U Berg 42 special carb kit was installed and the engine was smoother than stock. You could now drive it in 4th gear at 35 MPH. The idle was actually lower and smoother than the stock cam in a stock engine. Then I installed a GB 300 cam. Still very smooth and driveable with only a slight trace of rough idle. This alone should demonstrate that the proper combination is critical to your project. Yes, the proper selection will provide good smooth power and driveability. It pays to get all of your parts from a supplier of tested and proven engine kits all at one place so they will match and provide the performance you are looking for within your budget.
Also see GB 801-CAM and GB 801-HEADS for additional information.