major problems, major fixes (bit rambly)

[magnethead]

My truck had a fuel leak on the return line going from the driver side tank to the switch. I just replaced that line, but it is still leaking, but a whole lot less. I'm currently burning fuel out of the tank so we can drop it...

but that was only 1 thing fixed. I've been watching my fuel gauge, and after 6 3 mile trips, i'm used up a "1/4" tank of fuel. On a 20 gallon tank. Thats telling me i have now gone below 4 MPG(!). I'll get to that later (along with why it's in quote marks).

We went and got some gravel from the local quary. The scale said that with only me in the truck, it weighed 6680 pound. I'm 160, that means the truck weighs 6520. The left side had "3/8" a tank of fuel in it @ 6 pounds per gallon. 6460 pounds. I forget how much the right side tank had.

I've got some sort of whine comming from my truck going down the highway, but I haven't quite spotted where it's comming from. It's a middle pitched whine, not as high as a straight-cut-gears gearbox nor as low as a loose belt. I have previously ran my rear axle (dana 70HD) completely out of lube and still driven it, but it doesn't seem to come from that far back. I've already checked the carrier bearing and all 4 yokes- all are tight.

My rear drums need to be serviced. We have (as previously mentioned) owned this truck since 1990. That's 15 years. We have never had the rear brakes even remotely touched since we've owned it. We're actually not sure when the last time they were serviced was. Is it true you have to remove the differential cover, drain the fluid, and remove the axleshafts to pull the rear brakes off? Also, being that everything (drum, springs, levers, shoes, wheel cylinders) need to be replaced, would it be cheaper converting to disc? I have been told that when this level of replacement is needed, it is over 50 dollars cheaper to do the conversion than to completely replace the drums (luckily GM has always used the 8 on 6.5 pattern, even on newer trucks).




What should I do about my rear Brakes?

What could the UWO (Unidentified Whinging Object)?


How long can I expect these rubber fuel lines to last. We've had the truck since 1990 and this is the first time we plan on replacing both lines going to the left side tank. We've already done said procedure on right side.

My fuel gauge isn't reading correctly. It is reading about 1/4 tank or so off. If it says i'm on empty, I actually have 1/4 tank left. This is true for both tanks. What's a probable cause?

How can I shed weight? I know if I only use 1 tank at a time, i'll have 120 pounds less weight than using both. What about the radiator core support? I've heard of using a hole saw and drilling holes (sometimes up to 5 or even 7). How much would I save per hole with a 1.5" hole saw? What's the biggest I can go, 2"? Being I have 4 different coolers up front (including the 4 core radiator), I'd like to keep it structurally sound. And removing the bed (as much weight as that would save me) is out of the question.

what about removing the tailgate? How many tenths of a mile per gallon is that worth in itself, both aerodynamicly and by taking that amount of weight off the truck?

If I re-install the air tube going to the air cleaner that goes to the grille, how many tenths of a mile per gallon is that, if any (based off denser air)? Or would giving it that denser air make the carburetor actually dump more fuel into the engine?

I probably wouldn't do this, but how much weight could be saved if I took out the front bench seat of my truck and replaced it with a pair of buckets from a newer truck from a junkyard or elsewheres?

Are there any other things that I may have forgotten here than would help me out?