Here's the link to
ARC International, only in Japanese though.
Here's some info and pictures from
SPL Parts
ARC cores are well known in Japan to have highest flow and superior efficiency. Their side mount intercoolers for the Z32 have the largest core size (8"H x 9"L x 4"D = 288ci) among all the competition: Stillen is 9.4"H x 8.4"L x 3.5"D = 276ci, Greddy is 6"H x 8"W x 4.5"D = 216ci, HKS is 10.2"H x 7.8"W x 2.5"D = 200ci. ARC intercoolers are engineered for superior flow, notice the excellent design of the end tanks. The ARC intercoolers also mount at an angle, reducing the angle of the pipe bends for less pressure drop and allowing a wider core to be used. Shown below is a slightly older version (also slightly damaged), newer style is nude aluminum and does not have the black coating/paint.
They are quite expensive compared to other SMIC's but I may be able to buy a set of used ones.
/Fredrik