[oil pan 4]

Now that I have the carb running the way I want I got fuel mileage up to around 8.5mpg and I discovered I had a small fuel leak at the carb. I don't know how long its been leaking or how much it leaked.
I got the leak fixed and refilled to test. I will be driving it for the next few days to get an idea what the MPGs will look like.
I am not burning through most of the 40 gallon tank. So sample sizes are kind of small, not looking for precise numbers, just trying to establish trends.

The engine has gone from running wildly rich qjet carb netting 6.5mpg to running correctly with a different carb. I don't know anything about the q-jet and don't care to learn or have to time to figure out a different fuel induction system when I already know the edelbrock 650cfm and have all the stuff to tune it.
I also bumped the base timing to 12 degrees of advance. The distributor is untouched beyond that.
Now at cruise I see 15:1 to 16:1 air fuel ratios. Lean idle barely registers on the gauge, showing OL and flashing high 17:1 numbers some times.
WOT air fuel ratio stays between high 12s and 14 to 1 most of the time.
No matter what I do to try and lower WOT air fuel ratio it always effects cruise air fuel ratio too, lowering it.
Its also on a cold air intake, for now. Not the best for fuel economy.
It runs like total crap when cold.
The engine runs better, except when I first start it and its still cold, it has more power since the engine is not being suffocated with fuel. In this quest for better fuel economy I have made this vehicle pull better and run stronger through its entire operating range.
Because I always hear people whine that if you want more fuel economy you have to give up power and you wont be able to tow as good. That is not always true.

I had an accelerator pump problem that I fixed. I thought the engine was not getting enough fuel from the accelerator pump because of the nozzle size turned out to be the accelerator pump not working or barely working at all. Having a non functional accelerator pump and it not effecting the operation all that much after the engine made it to operating temperature I may try switching back to a smaller nozzle or using less pump plunger stroke.
No accelerator pump really makes it run badly just after start up. A smaller accelerator pump or less pump plunger stroke may be sufficient for normal driving.

So any one can improve the MPG of their old out dated tow rig with a gas murdering motor. All you have to do is tune the carb, shouldn't matter if its a q-jet or edelbrock.
That is a 30% improvement, with a fuel leak on the side of the carb.
I am thinking max MPGs driving around town in a suburban with a 7.4L engine, non over drive, non lockup transmission and 4.11 gears has to max out at 9 or 10 MPG.

Now I have to figure out, am I going to put the 3.21 gears in now or after the diesel and its transmission get moved over?
(this will effect how strongly it pulls but who cares, its getting a completely different twin turbodiesel drive train here pretty soon, this will be just for fun)

EDIT: I just realized, I never changed the spark plugs after I got this rig. New plugs should help a little.