No reason not to use the Transgo Shift kit. I've sold transmission parts to virtually every transmission shop in Western Canada, and Transgo hands down was the one they prefered. There was a company called Superior that came out with shift kits I believe in the 90's and some builders prefered them for front wheel drive GM's in particular.
The biggest problems I've seen with shift kits, is the person installing them DOESN'T FOLLOW THE INSTRUCTIONS. I had a guy come into our warehouse one day complaining that the kit he'd bought for his GM TH350 caused him to lose 1st and 2nd gear. He put the box down on the counter and there were a lot of left over parts. I asked why he didn't use all the parts as the instructions tell you to, and he said that a buddy of his said they weren't needed. I asked if his buddy was a transmission builder or a mechanic and he said no. Nice wasted valve body now.
What some have found, myself included is the Transgo TF2 kit shifts a little to harsh for their liking. If you want a firm shift, then use the TF1 from Transgo. By the way, a HARD shift is not necessarily a good shift. What you want from a kit is to cut down on the time clutch packs are applied.
Any how, go with the transgo TF2 or TF1. You said that the kit number was a TF2HD2. Make sure it's not a TFODHD2. That kit is for the A518 series overdrive transmission and WON'T work on your TF727.
By the way, I believe that Gil Younger (the founder of TRANSGO), was the inventor of shift improver kits, and most other kits copy his thinking in many ways.
