'92 Oil Cooler lines?

My '92 with 4.3L, automatic transmission, 2 wheel drive has a persistent oil leak coming from the front left in the engine compartment. The vehicle has 148,000 on the ODO. I can never see the leak at idle. Do you think the culprit is the O-Ring in the cooler line that attaches to the radiator? I just about have everything else buttoned up on the old girl except for this leak. Any help and direction you can give me on this will be appreciated.

Charlie M.
Dallas, Tx

I have read about a lot of oil cooler lines leaking. I just had mine replaced at 50,000 miles. I think GMC should be replacing them for free or find a fix...Oh, yes, GMC did find a fix...they quit making the Jimmy.