id boost the gsr motor over the h22. I hear the h22 has especially weak sleeves prone to cracking in even all motor applications, and above 8psi is really pushing it on that motor. A gsr can take more on the stock internals than an h22(not a ton more, cause its still open sleeved, but a little more), but for an all out, built engine, h22 is obviously the better choice becuase of its size.