trans problems

Kim's right on. What is happening is what's known as shift overlap. It's when the front band is still applied momentarily while the front clutch applies. Basically your in 2nd and 3rd gear for a second at the same time. I never use 5.0 levers anymore because most of the time they cause overlap, even if you use both springs in the front servo, 15 springs in the front clutch, and install the restrictor. A 3.8 lever will generally give you a nice clean 2-3 shift and be plenty firm for the 1-2 shift. Do not run it much (just enough to test it) until you get it worked out because overlap is detrimental to a transmission.