I have a 89 4x4 f250 So I have looked into lift and level kits I really want atleast 35" tires I have read a lot on here to upgrade from the style front axle that is there to a stright axle so with that said any ideas where to get one? what to look for? And can I just get a set of leafs that will bolt right in the factory position that is there now? If so does anyone know the length of these springs

 

My axle came out of a highboy that a buddy of my dads was scrapping years ago and my dad bought the Dana 44 HD Low Pinion (used in the F250's in the 70's) for 200 bucks which was cheap for even 20 years ago. So with that in mind, trucks of that vintage are getting scrapped left and right and a lot of those guys that are scrapping what's left of those trucks would more than happily part out what's sitting there. Especially because a straight axle isn't worth more than 100 bucks in scrap weight. Although, a Dana 60 from the same model year as your truck (from an F350) would be almost a direct bolt in swap. The downside is that people want a grand or more for the D60 up here in WI, I don't know where you're from but I'm sure it's not much different.
When I put my D44 in I also put F350 springs in the front and that gave it 4-5" of lift and I made hybrid spring packs for the rear using F250 and F350 springs to make it level. I can clear 38" tires with no problems. But you can't use the F350 springs over the TTB axles.