Gentlemen, I just purchased a 1994 4x4, auto, Cheyenne 3500, 12 foot dump rack with 94,000 miles. Questions are as follows: 1. Can you decifer the following VIN 1GBHK34K0RE252958? I would like to know the engine size and differential ratio. 2. How do I know if the engine or trans is original? 3. Did the 1994 year still use carburators or had they gone to EFI? 4. The truck needs a new exhaust from the cat back. Do you recommend OEM equipment or something else to increase the horsepower and /or gas mileage. Thank you.