I installed a B&M shift improver kit (RV and heavy duty stage) on my 88 K1500 5.7. After getting it all together I drove it about 3 miles and it wouldnt shift correctly. I also found out I didnt have reverse. I took the pan and valve body back off and found that I didnt have the snap ring fully seated in the pressure regulator valve. I re-installed it correctly and put it all back together and I now have reverse, and it shifts nice and firm from first to second, but when it tries to shift to third, its like it goes into netural! Did I hose my tranny? If I tromp it, it will go back to second and finaly shift into what I think is fourth. What do I do, or look for??? I am positive it is all installed correctly this time.