Okay now I've just installed a throttle body spacer on my 1990 blazer with the 350 5.7L in it. Horse power went up and all that good stuff, but the shift points changed. They shift more hard and at a higher RPM. It's not that I dislike this change, I just wonder why it's doing this. I checked all the vacume lines and everything involved around there, nothing seemed out of place. Any Ideas?