New Fuel Tank/Sending Unit

Thats really good. I'm stuck at about 8mpg with my 460 in the city with 3.06 gears :)

I can get 12 hwy with 4.10's and a Zf-5. Always 10 in town.
My 4wd truck's tare weight is 6270 and it has a lumber rack.

Hard to imagine that a 2wd w/ 3.06 can't do better.
I suppose that says a lot about the C6's ability to turn torque into heat?  

Mines not doing too bad then with the DSII swap and new carb. Have the NP435 w/ 33’s and 3.08 gears. Getting right around 14 MPG. I need to get my speedo gear sorted out though, clocks in abt 7-8 miles slower than I’m actually going. This week I’ll probably pull it out and see what color it is and L/R gear orientation.

You can use the speedo gear calculator, here on the site.
If you have a GPS speed, or distance from your phone.  💡

mine has always gotten between 12 and 14 since I bought it. a bit worse when pulling a trailer full of shingles or whatever. as far as range the best it ever did was 260 plus one time when I was trying to be extra careful and go as far as I could. but that was certainly not the norm. heat generation is an absolute waste of stored energy yet a loss that cannot be eliminated.  reduced is all. my biggest issue is keeping the speed down. its so hard to do.

Does the gearing matter a whole lot in the city (I know I made it a point to mention gears but wondering) ? I assume you would always be on the proper gear to keep between 1-2k rpm. On hwy the advantage is clear.

In fact I think you are more likely to be able to pull at lower RPMs in the city with a 4.1 vs 3.06

I miss "Big Red" 460/T-19/4.1... I was driving city all day at barely over 1K rpm

Thx ArdWrknTrk…I’ll check out that calculator for sure. I have a MPH app on my iphone that works well.

I’m fine driving anywhere in the City as far as my gearing. The only time I have a slight issue is getting up to speed on the highway. The NP435 is strange in the sense that 4th gear has a high gear. So even if I rev out third once I shift to 4th it kicks in at a really low RPM so it takes a sec to get up to highway speeds. Must be the way these tranny’s are, I just had mine checked internally and new clutch, flywheel, ect installed about a week ago.

The calculator is at Documentation/Driveline/Calculator.

gear ratio is a major factor. often misunderstood. I try to consider total gear ratios meaning the gear ratio of the axle multiplied by the gear's ratio of the trans. 4.10:1 gear multiplied by a manual shift 1:1 fourth gear is a good starting point. that converted to an od of .70 is equivalent to a 2.87:1 final gear.  now consider the other end of the scale. if first gear is 3.0:1, multiplied by that same 4.10:1axle then the total first gear ratio is 12.3:1.
 to put in perspective. a c6 with a 2.46 first gear and a 1.1 third through a 3.00 gear axle would be a total first of 7.38 with a third of 3.0 plus hydrostatic loss. this would be a typical f250 of the early 80s. also when the national speed limit was 55. rolling down the highway about 1750 rpm. today that same truck is doing 2700rpm trying to save face among the average camry crowd and running a bit above the efficiency of the 2barrel.

Well, I never need 1st and if I short shift I could be in 4th before 30mph.

But my worn Zf-5 doesn't like to be lugged and I'm almost always at 2k.

4th is 1:1 just like a T-19.
Highway speed around here is 80-85 without traffic.
I'm literally pushing a Brick into the wind.

In town could be better... perhaps.
Fuel isn't worth wasting time and I am a decisive driver.
Having front wheel only makes me consider turning, because the front axles bins and jerk around.

Having front wheel only ? (because rear axle is busted?)

Like a fragmentation grenade.

There are plenty of pics, I even started a thread.
But since I'm broke I have to keep going until I can afford parts.

Wow. Wonder what caused that.

Hope you can find a 4.1 axle from a parts truck somewhere. That maybe a cost-effective way.

And here I am with a spare 4.1 with 93K original miles (Axle C5-Sterling 6250 Limited slip) from my parts truck I would let you have if you were local. Serious.

Damn, Darth always got a solid 10 except towing the 5th wheel, then he dropped to 8. That was carbureted 460, C6 and 3.55 gears. His tare weight is 6400 lbs.

The Edelbrock 1411 750CFM on "Big Blue 2WD" is almost 10 years going. Wonder if I'm running too rich. What's the best way to check A/F ratio while running ? A/F meter ?

a/f meter is the best as a simple measure.

I can find them, but no one will let me open it up and look inside, before paying and dragging it home.
30 day exchange policy

I'm not going to screw around, driving over an hour each way and dropping $800, nor going to the effort of changing out an almost 40 year old often neglected and abused part.

I just don't know enough people any more.
Was a time I could have one of those complete, from the spring perches (tires, and all) for free... tomorrow.

that is a strong point. a lot of expense still on a mystery when rebuilding yours will give you a known result.

It's also 21/2* hours away.
Driving Highway on the front wheels is much easier than turning, as we discussed in the 'jerkyness with hubs locked' thread about driveline angles...

CV's (like THAT French brand) would be a godsend.