997 cab .. get the rear drains cleaned out ..
Voltage check on the alternator and battery for voltage drop .. starter lead and power distributor board fault will show on that check .
Exhaust silencer brackets crack and rattle .. easy enough to see underneath
Exhaust flange studs .. make sure they have been changed ..
Tandem Pump .. make sure its not too corroded
Check shocks for dampness
Check front coolant crossover pipes for corrosion .. expensive
Ill leave any engine faults as i dont want to jinx this !
Hopefully .. you will loose your title
Good luck .