Transgo or B&M shift kit?
Haven't used a B&M transpack but I have used numerous Trans-go TF-2 kits and they have always worked great. The only issue I have ran into with them is they tell you to grind down the throttle pressure valve to .281" (9/32). I no longer grind any off of it because every one that I've taken down to their spec don't seem to want to kick down (passing gear) automatically above 35-40 mph even when the throttle pressure linkage is adjusted to the max. By not grinding the valve down it makes tuning the kickdown easier IMO