My 2011 GT is hard to get into 4th gear from 3rd on the up shift, sometimes it goes right in, sometime it will not at all and just grinds. It does go into 4th gear most of the time when I down shift it from 5th but not always. It has a barton bracket with the stock shifter. Does this sound more like a shifter issue or a trans issue. I am going to order an MGW short throw, I have read they help with lots of shifting issues. The clutch and line have already been replaced. If I do need to remove the trans for a rebuild will it come out with the long tube headers in place, they are PYPES brand?