Well my tune came today it is the 91-93 dual tune,this thing is freaking awesome.Before the tune I couldn`t get my 305`s to spin unless I was on loose gravel now I can smoke`m till I decide to stop.And no more dead spot from 0 to 3000 rpm, now I can just stomp the gas pedal wihout holding the brake and spin the tires.I never expected this much performance from just the pcm usually you have to pull a motor apart to get results like this.I had the HPPIII until now and there is no comparison what so ever, to everybody that is not sure whether or not to get a nelson`s tune if you want performance this is it, plus you`ll not get customer service like allen gives you anywhere.