hey everyone, I just purchased a 04 gtp about a month ago and after a few weeks of me driving it there is no surprise that im running into a issue. the transmission seems to be slipping...all gears above 4k rpm start to jerk then eventually shift. I did put a jug of lucas transmission fix in her but the problem is still there.. so im guessing in the near future im going to need a transmission... ultimately my main question is... I have a spare transmission from a 98gtp.. can I use that? also could it be that the transmission is not slipping and its a common error to jerk and whatnot... let me know asap please. thanks guys