Please Help!

[Mikedaddy]

I have a 1995 ford mustang gt with 5.0 manual transmission. Ive had it in storage for a year or so and i pulled it out i have been driving it and its been bogging down a bit. While im driving it feels as if im letting off the accelerator for a brief moment and back on it and its a contant feeling in all gears but when im in 5th gear the stick starts to shake like crazy any of you have this problem? Ive tried flushing the fuel system and cleaning it new fuel filter now throttle position sensor still nothing is changing vac lines are all good makes a small distinct rattling sound but i cant tell where its coming from