I just got my stock bottom 6.0 running. Just wondering what to expect for mpg. Its a Carb 6.0 here is what I got

750 double Pumper, 620 cam, 240 duration 108 c/l, fully ported 317 not milled, gm single plane intake, 350 trans 4000 convertor, 410 gears with a 12 bolt, my truck should be around 3300 lbs. I got headers, flowmaster mufflers.
I was hoping for 14 to16 mpg

 

I am not an MPG expert but I don't think you will get that (14-16) with 4.10s and that cam...not at 60+ mph, anyway. If you had an overdrive tranny such as the 200-4R that would help. I know of a builder that has them rated up to 1000hp if you're worried about strength.

 

a 2wd 2500hd only gets like 16 highway and they have 4.11 gears

 

and they have an automatic overdrive transmission to aid that as well... not looking good!

 

Well I'll be finding out in a week or so. The 2500 hd has a lot of rotating mass it has to move. 50 lbs a wheel, a few extra pounds like maybe a thousand or more.

 

Don't forget that driving style is a HUGE factor in the gas mileage game.

 

And they have the much better gas mileage, computer controlled fuel injection...also not looking good.

 

its subjective,
too many ppl assume carb= bad mpg
but really its how well the carb is tuned for the motor its on top of and if the cfm rating, jetting, etc. is correct.

 

I agree.
A carb should get the same fuel economy as fuel injection if the air/fuel ratio's are the same.

 

10-12mpg w/4.10s
4.10 eeek might kick yo ***.
might want to run some 3.42s or 3.55s 14-16 and drive it right.
i had close to the same set up and even ran a 28" tall tire all the time
650dp holley
but keep us posted.....

 

28" tires, 3.42 Eaton Posi 10 bolt, LS1 4L60E, 27 mpg hwy.

 

 

That works out to 1800 rpm at 65 mph. I had a '78 Camaro, carb'd 350 with 700R-4, 3.08:1 and 26" tires, it did 26 mpg at 65 mph, which also was 1800 rpm. I strongly suggest 1800 at 65 if you care about mileage.

 

I would think it's possible to get 14 to 16 easily if you have it tuned spot on. If not, who knows then.

 

i think barely touching double digits if it ever sees them

 

My '05 HD 2500 has the 410's with the LQ4. 13-14 mpg is it for me. Good luck.

 

I believe that has a 31" tire also, correct???

 

Well my truck is not doing the best for mpg. I just can't keep it under 3500. It's a blast to drive. I think I need a new Carb I'm getting a backfire and the truck will cutoff. But it will start right up besides that it's super fun. The weather in Chicago sucks

 

When I had my stock carbed 6.0 w/small cam (206 210 duration) in my 63 chevyll w/4.30, th350, and 28" tires. I got 11 mpg without carb tuning.
I think 12-14 can be done with a carb.
derrick

 

I'm looking to buy another Carb. I'm going to start back driving it after the first