Ok, What have I done now... (904 problem?)

here is what i would do. if it were ME, i would get a clean drain pan, drain the transmission fluid, take the "spacer" out. button it back up using a regular filter. fill it up again. make sure the kickdown linkage is not getting tangled up on anything. make sure you are pumping fluid THROUGH the radiator cooler and that it is free flowing. take it out and manually shift it a few times through the gears and go from there. i use a full synthetic ATF+4 . you are good there. if it is not dropping from 3/4 over the full line, dont add any more, thats pushing it IMO


do you still have your stock pan?
i would reverse everything you did to it just to be sure your upgrade isnt causing the problem