Rear end change for '64 C 10

[cbittleston]

I am preparing to drive from California to Louisiana and want to take my truck, but as it is now it is not fit for freeway driving. I've heard that there is a rear end off a Chevelle that will make my original four speed with compound low something closer to a true four speed. Can anyone give me any hints as to the exact model I should be looking for? What will have to go into making the changes? My truck is a two-wheel drive Fleetside with the long bed and the original 235 straight six. I want to change as little as possible. Thanks!!!