You don't mention how many miles you have on it, but I'd assume it's over
100K, just due to age. You also don't mention whether it's a 4 or 6 cylinder
engine, but it really doesn't matter - try replacing your valve stem seals.
It's not hard to do - use compressed air to hold the valves in while you
break free the spring retainers and replace the seal cups... and I bet
you'll notice a big difference in oil usage. That is, unless you've gotton
the engine real hot and taken the tension out of the piston rings, but on a
Trooper, usually you'll blow the head gasket first.
Hope this helps.
r/
Steve