magnaflow

Remove the wire from the sending switch at the tank and ground it to the chassis. The gauge should read full. If it does the prolbem is in the sending unit. If it doesn't the problem is upstream. Next remove the instrument cluster. One side of the fuel gauge has voltage, one goes to the sending unit for grounding. So ground the sending unit side. It should read full. Make sure the gauge is securely attached to the dash. The nuts can come loose. Check all instruments.If it doesn't read and the voltage is on one side and the ground on the other the gauge itself is bad. Remove it and check solder connections. Heat up the connections as the insulation / varnish in the wire can interfere and cause high resistance. Magnaflow in Oakland

Magnaflow here, a new member The load on the engine is going to be high because of weight and wind resistance. The faster the engine turns so that it is in the maximum torque range is the best place to be. If below that RPM the engine vacuum will be lower and lower the fuel mileage . You will have more power and economy with a higher numerical number rear end. I have and 89 V6. It has the 4.10 rear. With two cold air induction tubes mounted on the front grill, from 4 cylinder models and off course Magnaflow mufflers and converter and 2 1'4" pipe exiting behind rear wheels I can barely pull overdrive at 65 mph. It is turning 3500 rpm in 3rd and 2700 in OD. Locked up. The engine feels best around 3200-4000 rpm. So I am planning on going to a 4.88 rear end Should end up with 3300 rpm at 65 mph and much better acceleration. Also this gives you an extra usable gear. So that makes hill climbing much easier too. Right now I get 12 mpg at 65 mph. Let you know what happens, total weight is 6600 lbs wet on a 21' Dolphin rear bath. Magnaflow in Oakland ca.

How far down did you run the tank? Your gauge might be off. Magnaflow in Oakland ca.