From the looks of the bend I would guess that it was put there when Toyota went from the 2nd gen. truck to the 3rd. Looks like a clearance issue is the reason for the bend. Maybe when they redesigned the truck they may have either accommodated for the EFI or they may have had to put a bend in it to accommodated for a sleeker hoodline. 
Have someone with a second gen take a look and see if it has the bend and also have someone with a 3rd gen look at theirs and report back the results to you.
X2
But what's to keep you from loosely bolting either of them up to see if you'll have any clearance issues or issues with connecting vacuum lines?
I would say try hooking the one up with more vac lines and if you don't need all of them just cap off the ones you don't use
. Then if there is a clearance issue try the other one. The manifold can be swapped in just minutes and you have the luxury of possessing both manifolds just to try and fit one of them. Then you can be the man with the knowledge to answer this same question in the future
Good luck!
