Just so you guys know we are soon to be offering a sonic thickness probe for checking cylinder thickness and head thickness for porting. We are offering Landtek's TM-8812 unit and can pass on the initial group buy to members of the forum.
We are looking at a discounted price of $259.99 to members of the forum. These sonic units retails for about $500 ea and we will probly be selling them in the 350-400 range. If you have been thinking about sonic checking your blocks/heads/????? yourself here is your chance to get a real deal on a great item.

Here are the specs

Contents in the package:

Main Processor with Calibration block (5.0 mm)
Standard Probe: end diameter: 8mm for measuring range of 1.20 - 200 mm, or 0.047 - 7.874 inch, display in both mm and inch.
A Bottle of Coupling Paste
Four AAA Batteries
Operation Manual
Carrying Case
Features

THE TM-8812 is a handheld microprocessor-controlled ultrasonic thickness gauge specifically designed to measure the thickness of metallic and non-metallic materials e.g. aluminium, titanium, plastics, ceramics, glass, plastics including rubber and other good ultrasonic wave conductors, as long as they have parallel top and bottom surfaces. With applications in many areas of industry, the TM-8812 can perform precise measurements on various types of raw materials, components, parts and assembled machinery. It can also be used to monitor all types of pipes and pressure vessels for loss of thickness due to corrosion or erosion. The TM-8812 is easy to use and, after a simple calibration to a known thickness or sound velocity, the gauge will give accurate readings to an accuracy of 0.5%.

Sound velocities for 11 different materials can be pre-set and thickness readings can be stored in the memory and downloaded via the optional RS232c output.

The microprocessor allows fast data acquisition and analysis.
This new tester features a wide measuring range, high accuracy, ease of operation, low power consumption (Four 1.5V AAA batteries), and convenient data display.
Communication with computer is avaliable through standard RS-232 port (at an extra cost of US $59.90).
Applications:

Metal Materials: Al, Fe, Stainless Steel, Cu, Brass, Zn, Ag, Au, Sn,....
Acrylic Resin, Water Glass, ...
Other materials with known sound velocity values.
Specifications

Measuring method: Ultrasonic pulse echo
Measuring frequency: 5MHz
Measuring range: 1.2 - 200.0 mm or 0.047 - 7.874 inch (steel); Actual range varies with the types of material measured
Accuracy: +/- (0.5%H ¬± 0.1) mm
Sound velocity range: 500 - 9,000 m/s
4 digit large LCD display (in both mm and inch)
Automatic power-off after being idle for 4 minutes
Probe contact indicator
Resolution: 0.1mm or 0.001 inch
Working temperature: 0 ¬?C ~ +50 ¬?C
Communication between tester and computer via RS-232 port (optional)
Size: 120mm x 62mm x 30mm (4.72 in X 2.44 in X 1.18 in)
Power supply: Battery: Four AAA alkaline batteries (total 6.0V)
Weight: 160g (main unit); 40g (probe)