First of all, I've got a '90 EF sedan with a b18/92 GSR tranny swap in it. Runs GREAT except for recently after a fast run on the highway, I come to a stop and it revs at just over 1k and bounces slightly. All other times it revs normally at ~750 at a stop. Kinda weird and obscure - any ideas as to what the problem might be?

Thanks