Not too sure whats happening with my 94' Z28 on the hiway. At about 60mph when I want to speed up a bit the car shudders when I bring the speed up slowly. If I step on it there is no problem, Even if it doesn't down shift. It's an automatic tranny.
Any help would be great.

torque converter. Does it also do it from a stop or only at 60 mph?

yeah, TQ most likely. Sometimes this would happen on my 700r4 because it was in between lockup and non lock up.

I'm not sure that's a problem.

My 93 vette will lock er up tight, and stay locked up down to 40 unless I heve her nearly half throttle. At 40, she's pulling a locked up torque converter, overdrive gear, and 2.53 rear axle ratio at about 800 rpm's. I'd shudder too under that kind of load.

The vette has a light shudder trying to accelerate all locked up in high below about 1200 rpm. I consider it normal, and pull the stick back to third or step on the gas hard enough to get a dowshift.

thats a great point jim as an added bonus everyone should be eager to accelerate into a downshift.... i love the summer time.

The TCC clutch is controled by a switch on the brake pedal. If you want to confirm its the TCC causing the shudder, gently touch the brake (not enough to slow down) while it's acting up. See if the problem suddenly goes away.

Thanks for the Tips. I'll try that brake pedal technique as soon as I get out of this Deep Freeze!

Oh and no it doesn't do it from a stop it only shudders at hiway speeds.