Advice on a Mitsubishi Chariot 1996 N33W. My car Vibrates mild while idling...

[Jasmine L]

...and more when I accelerate.? First the fan died on the radiator, and my car was over heating which blew a head gasket.
So Hubby Pulled motor apart, put new gasket set in the bomb, new cam belt and other belts, Now shes running again doesnt over heat.
But when shes idling she sounds like she is trying a bit harder to idle and has a mild vibration, on acceleration the revs sound like the motor is trying harder than before and the car vibrates alot more.
Also I have noticed while the car seams to rev more, it doesnt switch into gear as fast, as it did before all this stuff happened. Now hubby thinks im wrong about the reving sound, I think i have driven it daily for a long period of time and know that my car sounds different.
She isnt as smooth, as before nor does she change gears at the right time. And she seams a bit more gutless, like shes trying harder, any I ideas would be great...
Cheers