Other than the usual Cold Air Intake is there any way to increase the Fuel Mileage on my 94 Toyota Pickup?

I have a 1994 Toyota Pickup with the Infamous 3.0 Litre V-6, The Engine blew up about a year ago and i got it rebuilt. They had to bore it out 20 Over because it burned a hole in the #1 Piston and scarred the Cylinder Wall pretty bad. Since then i have replaced the ECM, Mass Air Flow Meter twice, the TPS, The Distribitor was off a tooth among other things. I have had to take it back 3 times for Oil leaks and the Valve Covers are leaking again and the Check Engine Light is on and the Code says it is a Lean Malfunction. ( Does anyone know what may be causing the Lean Malfunction??? I need to get it right the first time because i dont have the money to be guessing). There are like 7 things on the list. Thank You for any assistance.