HELP? front axle shaft discrepancy

[scavengerdog]

got a 98 jimmy. went to replace left front axle shaft. both auto value and napa shafts were wrong, had male inner end. thought they had left and right mixed up, got the right side one, looks close, has female inner end, but too big. called the gm dealer, they ran the vin# and faxed me a pic of the axle shaft that allegedly cam in the truck. looks just like the aftermarket ones... wrong. can't get a good history on the truck so don't know if axle was changed, but looks like regular front axle/differential assembly. anyone?
Edit: i have already had the axles out. the left is not as it is supposed to be. ended up just putting new boots on it and reinstalling it until i find an answer.