Interesting. Your flex plate would fit my 383 motor at 2.16 but would not fit the 440. That crank flange is about 2.19. I remeasured tonight after work and I initailly stated the two were different by .025. Its more like .030. I called Brewers Performance today and they tell me the same thing. That flywheel should absoultely fit the 440. Is it possible that on the assy line the motor was first done for a 4spd car due to the sleeve being present in the flange hole and then chnaged because of the out of spec size on the flange? Much easier to modify a flex plate than a flywheel. Brewers can sell me a stock flywheel and open that flange opening in it to 2.195 so it will fit my 440 and not have balance issues. Thinking about going that route.