my occasionally used parts hauler just blew the trans. i just bought a 99 dakota 2wd extended cab with a 6 1/2" box to replace it.
has 123,000 miles with a 3.9 V6, auto trans, with a lot of power options.
the trans was rebuilt 10K miles ago. tie rods, ball joints, brakes all around and exhaust have been replaced in the last 5K miles.

it has a slightly rough idle that i think new plugs, wires, cap and rotor should fix. or is a slightly rough idle normal on these trucks?
also what kind of repairs will be looking at in the future?

THANKS for any info you can give me in advance.