Having problems

I am having problems out of my 1997 tacoma. It has a "6 lift with 33s. I have it geared 4.56 but it seems to be jumpy and sputters at times. It never happened until I re-geared it and I was wondering if maybe i geared it too low? Would a 4.88 gear set make it run smoother and better for my driving conditions. I do most of my driving on the highway. It is a 5 speed with the 2.7liter in it. Rpms is somewhere around 3 grand in 4th at about 55 mphs. (I think b/c my odometer is off)..lol

Jumpy and sputtering is most likely problems with the motor, but nothing a full tune up, good synthetic motor oil, and injector cleaner shouldn't fix. 4.56:1 gears are a bit tall but should be just the ticket for highway cruising. 4.88:1's would be better off road for your 4banger but you would be running some high rpms at 75 mph on the highway.