BudRacing

iTrader: (3)

Yeah, I wouldn't suggest replacing the pulley. It's a bit of a pain and a very expensive part if you're going with one of the aftermarket pieces.

Schiavonske1013

iTrader: (1)

Oh yeah I’ve pulled several off these trucks it’s not fun, but having a shop and the proper tools at least helps.

TXsilverado

iTrader: (19)

Harmonicbalancers are easy and cheap. Visually, how does the dampener look? How many miles on that belt? Motor mounts? I would eliminate drivetrain since youve had different transmissions, converters and it does it in park.

Sometimes a 50 rpm change can fix things, but that wont help in the 2k range....maybe idle changes and timing/fuel changes in those rpm ranges. Spitt balling here. Start with the easy solutions.