the gap between the flex disc in my car (if it is bolted to one of the flanges) and the driveshaft is about 5/16 inch. is this normal. I've done the flex disc on this car before, but i don't remember if there was that much of a gap.

some background.

the car is a 7/91 525i with 4l30e gm transmission.
about 4 months ago i bought a used transmission for this car from vines automotive. i asked them twice if the item would fit an e34 (the used box is from an e36). they said yes, so long as you change the output flange (didn't tell me this until i went to pick it up). they also instructed me to change the output tailcone. i did such. both cone and flange on both transmissions measure to approximately the same length when swapped. the used transmission fits perfectly into the transmission mount holes. if the aforementioned gap is too big, what could have possibly happened? thanks.