Gary, call John. I think he will be honest with you about real ET improvments. I would bet that you are dealing with less than .15 seconds MAX because of the weight loss. However the gearset is better than a glide, but not as deep as a 3 speed so it may work out really well in a heavier doorslammer. The HP loss argument I often see on the net makes me laugh. It takes X amount of power to run Glide, TH350, or 400. Whatever the number is that week. Any reasonably intelligent person can figure out that a particular transmission doesn't take "X" amount of HP to "turn". The numbers I commonly see are about 15-20 for Glide, 30 for a TH350 and 45 for a TH400. I dunno about you but I can turn the input shaft on any of them by hand. :laugh: I've also never noticed having to adjust an idle speed screw because I swapped from a Glide to a TH350, or a Th350 to a Th400, etc. All that extra HP consumed by the bigger trans ya know. The power loss does get greater with heavier parts but only while you are accelerating or decelerating the heavier mass. There is mininal HP consumed while the parts are rotating at a steady RPM. An object in motion tends to stay in motion and all that. My experience is that the difference in weight between a TH350 and Th400, which is almost exactly 10 lbs all of it being in the rotating assembly, will only cause about .03-.06 or so difference in the ET on a low 11 second-high 10 second car. 10 lbs less total weight on the car, 10 lbs less rotating mass, and .04 difference in 1st and second gear ratio, all of it being an advantage for the Th350, and a car only slowing down about a half a tenth.. Some cars go faster with the TH400 for whatever reason. To me, the biggest advantage of lightening the internals of the TH400 is it reduces the shock on the intermediate sprag, and lessens the wear on the clutches.
