Thank you.Just about every K5 had 3.73's for gearing. Some in the 80's had steeper gears (3.08's and stuff). Depending on how large of a tire he wants, 3.73's might be just fine (33's or 35's would prob do fine). Another common problem the chevy's have is the frame likes to crake at the steering box. Offroad Design makes a weld on and bolt on steering box brace to fix this. Other than that, just do some searches on here and look at peoples build threads to see what you can do. There are a lot of cheap ways to build these things, just have to search around. Hope this helps.