****e. I sold my Hi-Lift already and couldn't find any pics. I looked through 7 years of pics on Facebook and my entire Photobucket album. No luck. The lift jaw should be pointing rearward, and lowered almost all the way to the bottom. I stored the foot underneath it, where the bottle jack used to be. I believe I had to remove the clips for the long rod that came as part of the factory jack. That might be what's giving you clearance issues. Or maybe some of the padding under the carpet. I can't imagine the seat design changed from my '00 to your '01. It definitely fits though! And AFAIK, the only difference between your Hi-Lift and my old Extreme model is that mine had the clamp provision.
Edit: Just looked at your pic and I see you have the little extension thingy on the very top. My Hi-Lift did not have that. It was just straight bar. I bet that's what's giving you issues.
http://www.hi-lift.com/hi-lift-jacks/product-comparison.html
If you look at the comparison, mine had the clamp jaw bolted to the top. It used a wing nut so I just left it off and stored below. I actually never needed it. I'd suggest try removing that top piece and storing it separately. Idk if yours has a wingnut, but you might pick one up at the hardware store to make life easier, should you ever need it. I reckon you've already got basic hand tools in your truck though. With that said, having to bolt that little piece on with combo wrenches is only a minor sacrifice (if even at all), to be able to carry that Hi-Lift safely, securely, and completely out of the elements.
Give it a shot!