Difference between h22a (jdm) and h22a1 (usdm) would be the dome of the pistons. The jdm h22a is significantly taller, yielding 10.6:1 (compared to the usdm 10.2:1). The lobes on the camshafts between both USDM and JDM to appear to be different to the naked eye, but I would need to measure the lobes to be sure. The TypeS on the other hand does have more aggressive lobes, but the duration is very short. Skunk2 camshafts are more aggressive with longer duration, but dyno sheets showing that they actually make more are hard to come by.. I have seen very nice numbers from Jun's camshafts. But with any aftermarket cams shaft will require upgraded springs/retainers and of course tuning, tuning and TUNING!

-Mike