New jimmy owner!

[Burnout]

Evening boys,
I've been on the site a while back when I was looking for a jimmy. Finally found one that I liked. Specs: '85 gmc jimmy 5.0 auto with 8'' of lift and 35's. It's been modified into a truck. Pretty sweet. I have a few questions tho. The driveshaft is leaking where it goes in the transfercase. Any reason? I'm thinking it's because the driving shaft is to short. Also I was thinking of switching out the auto for a stick. Anyone done this before? And last but not least, anyone know good performance mods for a 5.0? I like the 5.0. Nice power and cheaper on gas then the 350.

Thanks peeps,
JR