Senior project
Your question is extremely broad.
What kind of offroader? Mud? Rocks? Trails? Driven on the street some/often? Multipurpose?
What is your budget? I cant imagine a high school budget being much. Starting from nothing a $1000 will be blown pretty dang quick.
What is your level of experience in mechanics and fabrication? Can you change your own oil if someone walks you through it or can you rebuild your own axles/engines/etc? Can your welds be described and chewed bubblegum or a row of dimes? I wouldnt bet on friends and family
helping on a regular basis for any lengthy project.
Do you have a decent place to work on a truck and tools to get the job done? A dirt driveway and a box of walmart wrenches your dad got 3 years ago for Christmas wont cut it.
ALL this being said...
For entry level, multipurpose, quick, cheap and easy, Id go with a 78-79 Bronco or F150. They are plentiful, simple to work on and are as good as any truck ever built directly off the showroom floor. Its going to be real common to find these with 351m/400s which will give you room to grow into a 460 as pretty much a bolt in deal. The biggest gremlin Ive found in any of these trucks is wiring. 30+ years of idiots with crimp connectors have ruined the wiring on many of these trucks.
For simplicity and cost effectiveness, stay in the 35" tire range with a little fender trimming and basically stock motor. Going big means going expensive...usually.
but what you want the trucks purpose to be is the biggest deciding factor on tires and size engine and the suspension





