Jeep Bucking at High Speeds

[xjnate]

Hello, I have a 99 Cherokee with a 4.6 stroker with about 6000 miles on it now. The stroker has all the typical mods, comp cam, ported head, ported intake, bored throttle body, ford injectors, etc... The only things that haven't been done yet are a 3in exhaust, currently its all stock, and a professional tune. While I love the power it makes and for the most part it runs great, the jeep has developed a problem that has me absolutely stumped. I used to drive it 40+ miles a day to school and after a couple thousand miles it began to buck or jerk randomly while driving down the highway. At first it was only very slight and occurred once or twice a drive. Now I have moved to be closer to school so I don't have to drive as far but the jerking continues to get worse. It only happens after the jeep is warm and at speeds of 50mph and above. Yesterday I drove 10 miles across town on the highway and by the time I got to my destination the jeep was doing this every 30 seconds or so, but when I parked it for a while then drove back through town it didn't do it all. Although the it gets me to school and work just fine I don't feel comfortable driving long distances to go off roading or camping, which basically defeats the whole purpose of having a jeep. I'm thinking its something more minor by the way it runs just fine around the city and when not warmed up, but the only things i can think of are a shorted wire in the ignition ( no clue where it would be ), the catalytic converter, or some dumb efi sensor. Has anyone had a problem like this before or can y'all think of what this could possibly be? All help is appreciated, but I do have an extensive mechanical background so please no newbie responses.

Thanks,
Nathan

[nicpaige]

I have seen these same symptoms when a converter gets plugged up.

[councilxvb32]

So Megamotormadness

[jeepxj3]

Ignition related? plugs, wires, cap, rotor, coil.
Performance Distributor has some nice stuff. http://performancedistributors.com/product/jeep/