There are many ways to approach this. In my 74 Challenger, I've got the TF-SC shift kit by Transgo. It's the smallest kit Transgo makes, and in my application it works just fine and dandy. Normal driving, it has just a little firmer shift. However, under full throttle and banging the slap stick shifter it has a much harder shift, and despite the stock engine(tuned properly), it will bark the tires going into 2nd gear. I didn't install the kit myself, as I had a very knowledgeable builder install it for me, and I think he had a couple of tricks up his sleeve to improve the kit from what Transgo had intended. No complaints though from me or the wife.
