Chevrolet Repair: Chevy truck drivability problem, antifreeze leak, chevy garage

Question
I have a 1997 chevy 4x4 1500 with the 5.7 vortex engine. 1 month ago i had a local garage install new intake gaskets because of a antifreeze leak. Upon picking up the truck after the repair i noticed what seemed to be a miss. So i installed new wires,cap,rotor and plugs. The problem still the same.I took it to the chevy garage and they said the cam sensor and crank sensor were out of alignment. They did the proper alignment and still the same.It's not a miss but it "BUCKS" when after accelerating you let off the gas to maintain speed.it only does it once each time you accelerate then let off the gas. The truck runs perfect other than this problem which it did not do until the intake gaskets were replaced. the local garage that did the gaskets has had it now for 2 weeks and he just called me and said " I GIVE UP COME AND GET IT". He is trying to tell me that the timing chain is stretched and causing a misfire. I don't believe this is true because it did not do this prior to his working on it, and the chevy garage agrees with me. The truck has 169,000 miles on it and very well taken care of from new. It's almost like the engine shuts off for a millisecond.      Thanks, Joey

Answer
I would get a diagram, and make sure they reconnected all the vacuum hoses correctly. It could be opening the egr valve differently than it did before.
I would also check every electrical connection that was, or wasn't disconnected, but may have been tugged on.

I agree....not the timing chain, but it could be the timing, since they changed that.

Van