I found this yesterday at my local used book store and snatched it up faster than a Zingaran on a dropped copper! I had this issue back in the day, since lost it, and now have it again (See? Life is a circle.) and now we're going to take a look at it!
So, this is a valid question in the world of comics. But I'm not sure you're all going to like the answer. It all starts out like most What If... issues where the Watcher dude with the big head screws up and sends somebody where they shouldn't be. In this case, Wolverine lands in the world of Hyboria and it doesn't take him long to run into trouble. Specifically, trouble with flowing red locks and a sword.
But then Logan starts wanting to get in Sonja's chainmail panties and beats her in a fight and she's all like, "Okay, but I'm not going to like it." and then somehow they get sidetracked by Conan showing up and him and Wolverine don't get along at all.
So, down to the nitty gritty of the question, What if Wolverine fought Conan? The answer? Conan gets his hand cut off!
But, Conan being a badass and all, he just sticks the bloody stump in a burning brazier and cauterizes it on the spot.
Then some stuff happens and Conan gets zapped away, and then it ends with them implying that Wolverine takes Conan's place, becoming King of Aquilonia with Red Sonja as his wife! Bah!
But the funny part is at the very end, where the X-men are fighting some bad guys and out of this weird portal thingy pops this howling, one-handed Conan who just starts shoving his sword into Skrulls and other baddies. Then the X-men run away.
But for a real laugh, the Marvel gang included this final page of the comic...
B'waugh! Haw! Haw!