Welcome from Wausau WI! good to see more wisconsin folks on here.
idk about granny gears
granny gears could be the trans.
like granny low
check for RUST my truck was full of it.
rust in
cab corners
cab supports
rockers
fenders and inner fenders.
A picture would help alot!
look at my build look in these areas for rust. that i replaced
http://67-72chevytrucks.com/vboard/s...=355750&page=1
i would say its better to start off with a sound truck than a rusty one. its worth the money. but i know 67-72 are hard to come by in Wisconsin so if it is nice go for it.