Chevrolet Repair: vortec miss, deer in the headlights, gm dealer

Question
 I have 1997 k1500 z71 pickup with a 5.7 vortec an 5 speed trans.  The problem started efew month ago, engine starts missing, valves rattling, truck lurking, tach goes up about 1000 rpm higher, speedodometer instantly goes from 60mph down to about 20 mph, then comes right back up, up shift light comes on even when the truck is alreay in high gear and the ABS light comes on and stays on.  All this will last about 4 or 5 miles and then clear up as quickly as it came on, it may happen every 500 to 600 miles.  All this leaves no code in the computor.

GM dealer has replaced: crank position sensor, cam position sensor, sparkplugs and wires, cap and rotter.  Has left GM dealer with deer in the headlights look.   Left truck with dealer for a week they drove it every where and noting happened.  Got truck back and within 300 miles problem was there for about 6 miles then cleared up.  

Answer
Hello, I really don't have a answer on this one. I have never heard of ALL this happening at the same time. The first thing I would check is the grounds that go to the frame. I know one is right under the drivers door at the frame mount and there is another in the left front near the bumper mount.

Sorry I can't help more

Mark