i tried some experimental injectors last summer, that were set to 250. I had to skip the injection pump forward one notch on the timing belt because they needed extra advanced timing to offset the delay in firing. I kept advancing in increments and each time the performance got better, but the noise got louder and louder. By the time I got scared and stopped advancing, it sounded like a hino truck's diesel engine and performed like it still wanted more advance. I can say that 250 is too high.