Since no after-market performance pads seem to be available for the early girling calipers, here is a way to get real sports car braking for very little coin. I have done this mod twice "once with $9 repco heavy duty pads, and once with the metallic pads". Total work time should be about 1.5 hours. This mod will give better stopping power, less to no brake fade and more brake pad surface area relative to the stock asbestos pads. It will however increase the amount of leg force required to stop your car, so dont be surprized if your brakes feel different afterwards.
This tech note applies only to non modified early girling calipers that use the rounded bottom brake pads. It is imperative that you keep the brake pads clean and do not touch the pad surfaces with oily hands. Also do not inhale any of the dust generated by the grinding process. Read the instructions totally so you are not in the dark with future instructions before you get to them. You will need a bench grinder "or equiv.", a dremel tool, a sharp scratch awl and a fine eye.
Purchase a set of metallic brake pads to a 76 datsun 260Z. The Datsun uses calipers nearly identical to a later model alpine or tiger. I got mine at the auto parts club for $18 (PN 700-150M). The M in the part# designates metallic.
There are two obvious differences between the old vs. new girling pads.
a) The bottom portion of the pads are rounded "specifically the old pads have a 1.5 inch radius". The new pads are somewhat square.
b) The new pads have metal that surrounds the pad holddown pins. The old ones do not. Also the pins will not exactly the new pads in the caliper, so a dremel tool will be used to open the outside portions of the pin holes for fit.
Pull one of your old pads from the car. Clean the old pad thoroughly.
Place one of the new pads in the caliper with the metal side of the pad place toward the piston side of the caliper, but with the pad portion on the outside of the caliper. This will allow you to gauge the amount of metal you will have to remove from the sides of the pin holes on the new pads. Use a dremel tool with the appropriate size bit and grind until a slightly loose fit is secured with the pins fully installed through the pad and caliper.
Take the old pad and the new pad and put them back to back. Line the pads such that the bottom most portion of the new pads pin hole lines exactly with the top most portion of the old pads. This assures the pads are aligned how they will be used. A pin installed through the new pads pin hole, should just touch the old pad where the old pad was held in the caliper.
With a very clean pair of vise grips and very little force, squeeze the two pads together while adjusting their positions accurately.
Take the scratch awl and carefully scribe a line in the back side of the new pad, using the old pads side as a guide.
Remove the vise-grips and carefully grind the material off the outside portions of the new pad. Keep the radius slightly oversized as final fitting will be done with a file.
The sides of the pads will also have to be notched similar to the shape of the old pads so the pad can be rotated in the caliper. The exact shape of the notch is not critical, but don't remove too much pad backing as only a small notch will be needed. This is so the pad will freely rotate in the caliper.
Slide the new pad into the caliper and check for fit. Attempt to install the pins into the caliper and pads. It will not likely fit. You must now remove the pads and use a file to trim the pad so that the pins can be installed with a very small amount of play. Note that the pads should be able to freely rotate inside the caliper with the pins removed. The pads should be fully de-burred and smoothed with a file prior to final assembly.
Good luck!!!!