I Have 3:73's, I like them Alot.. My Buddy still has the Stock Gear and I Can Really tell the Differance...
I Just WOuld not Go Higher then 4:10's... <-- But i still would not even do that.. 3:73 Will Work out Good for you~!
The Tech Section Will Most Likely Give you all Your Answers.. Also Try the Search Option It Works Rather Well And Will Assist you with all Your Needs... Welcome to Stang-Net And Good Luck With Your Huge Build!
personaly if i were in the Market.. between 1000 and 1800 Pending on how Good The Body, interior, and paint looks... the Miles And the Small motor is Killing What you Should Get For a Fox..