Hello, I just got home from drag racing today at englishtown,NJ. I have a 1994 396 Lt1 stroker motor with a built 4l60e Tranny. While i was making my 1st pass today on the track I had a great launch 1.66 foot time but when it came time for the car to shift from 1st into 2nd gear it just kept bouncing off the rev limiter until i let off the gas and then press it again so the car would shift.As i did this a big puff of black smoke came out the tail pipes. It shifted through all of the other gears fine. It also has no problem shifting around town while driving normally. Anyone ever come across anything like this or possibly know a fix?