[jerry moss]

I'm probably going to step on some toes here but i'm guessing the blazer was posi front and rear and the bronco was open both ends. i owned a bronco with 4:10s and posi front and rear and it would climb almost anything, it didn't like snow/ice and soft mud with posi front it wouldn't turn in the soft stuff, it plowed straight ahead. my 72 super K20 was also posi front and rear with 3:73s and would go almost anywhere too, just couldn't fit in tight spots the bronco could. i really like them both and they both performed quite well in the mountains here in the sierras. just my 2 cents.
my dad has owned 4x4s since the early 50s and i learned to drive in his 70 stepside 4x4, until he stopped driving several years back he could still scare the he!! out of me where he could put a truck and get back out.