I have a stock GN tranny with a Art Carr shift kit, I installed a PTC 10" lockup 3000 stall converter and a tranny filter and fluid change last winter. I put about 100 miles on it this summer and it shifted as firm as it did before, I took it out last night and I noticed a big difference on how it shifted, very soft like it did before I had a shift kit installed. The fluid I used is Valvoline Dextron VI synthetic, is this normal or am I having issue. Also I really don't beat on my car, just cruise with some WOT blasts, it still chirps the tires from first to second when in drive. Thanks, Kyle.