1965 1200 with Shorrock supercharger

I still have the original matching number on my 1965 VW Beetle

The obvious change for 2012 is the Shorrock Supercharger that replaced the Judson Supercharger

Hhow many useable VW Shorrock Kits still exist? That's a difficult question when we don't even know how many VW Shorrock Kits were produced...estimates range from 300 down to less than 50 produced. 

So in short it's very very rare!

From: http://ofdc.forumactif.org/t85-the-shorrock-supercharger-history-and-technics

So why the Shorrock Kit cost so much more than the Judson?
The Judson blower is of the sliding vane type, where the vanes slide in and out of an eccentrically positioned rotor, sealing against the blower chamber wall through centrifugal force to produce the boost pressure. It’s simple and effective but does produce extra heat by the friction action of the vanes in contact with the casing so the unit needs extra cooling and lubrication through an external oil supply.

One of the strengths of the Judson was it utilised virtually all the stock hardware. You just bolted your Judson to the intake manifold made a few minor adjustments and in about 4 hours you were up and running. However these Judson strengths could also be considered their weaknesses, in that using the stock fuel pump, carb etc was a compromise in an effort to keep the price down.
The Shorrock is also a vane supercharger but a fixed vane and very much more complex in construction. The vanes are held away from the chamber walls at a constant clearance of about 1 thousandth of an inch, which means no heat build-up through friction. As a result the Shorrock runs cooler than the Judson; it also produces more power.

The Shorrock Kit for the VW was made to function at maximum efficiency with little regard to cost. For example the VW Solex carb was judged to be incapable of delivering a precise amount of fuel throughout the rev range so Shorrock used a constant vacuum Stromberg carb and an electric SU fuel pump in place of the stock VW mechanical pump. The stock VW intake manifold was replaced by a wide diameter manifold with rubber sleeved joins similar to the later VW twin port manifold. These Shorrock kit refinements and the basic higher engineering costs explain the disparity in price between it and the so-called, “budget” supercharger kits.

EMPI sold The Shorrock in a number of packages from 1965:
The basic Shorrock C75bv blower kit as the PSSV-500 for the 40hp engine producing 72hp - $395.00
The Shorrock Kit with an EMPI Big Bore Kit, the PBBV-100, 1352cc producing 78hp - $493.50
The Shorrock Kit with an EMPI 1500 Stroker Kit, the PSKV-601, producing 82hp - $684.50
And top of the range with an EMPI 1600 Stroker Kit, the PSKV-600 producing 85hp - $794.50
You see the top quality of the Shorrock Kit came at a high price for 1965…it still does.
So, what could you have expected for your money? EMPI quoted figures from a road test published in the April 10th, 1964 issue of “Autocar” magazine. The main points of the test emphasised the much improved engine refinement, which I can confirm as a six-cylinder smoothness. The reported top speed of 89mph from a 1200 Beetle along with greatly reduced 40-60mph time in top gear, chopping 11 seconds off the stock figures.

* Shorrock Supercharger
* Judson Electronic Magneto
* Big Bore kit from 1200 to 1385
* Bosch 010
* RaceTrim Valves Cover
* RaceTrim Oil Sump
* RaceTrim Air box
* Empi Oil Pump
* EMPI Fuel Filter
* Matching number engine