What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Big block guys

85 Jimmy

85 Jimmy

Sheepdog
 Premium
Joined
Dec 31, 2005
Posts
2,239
Reaction score
465
Location
Gulfcoast
What kind of mileage are y'all getting, and how is yalls rigs set up?
My blazer with 6" lift, 4.56, 37's, TPI 350, and a 700r4 gets around 7.5 MPG

I have a 454 that I got for free that I've been thinking about just trying to hone the cylinder walls out, put a cam in, and have some head work done. I'm thinking that the 454 may end up getting better mileage than the 350 just because it'll have to work less. Also, what would it take to get a 700r4 to be happy behind a mild 454? I have a 4l80e, but that'll take more money and time to get it swapped in.

I want to swap in a LQ4, but everyone thinks they are worth their weight in gold around here.
 
Many moons ago... my old K10 with 454 (Holley 750), 4spd, 4.56's and 38's averaged 11~12 mpg as a daily driver.

No idea on my current K5 but it appears to be really good on gas with a qjet. I used around 1/4 of a tank at Boggs & Boulders for 1/2 a day.
 
I went and pulled a tractor out yesterday. 50 miles round trip used a 1/4 tank. :pimp:
 
I'll run a hone on the cylinder walls this weekend and see what they look like. Then I may be able to put those heads I got from you to use.

The engine was in a flooded RV from katrina and when I got it the pistons were seized in the cylinders. I let them sit in ATF for a few days and then pounded the pistons out. There's some surface rust due to humidity on the cylinder walls now, but they may not need to be bored.
 
Phil513 said:
Seems like an injected 350 should be doing better than 7.5 mpg.
Click to expand...

That's what I was hoping for, but I haven't seen any better numbers in the last 1,000 miles. I'm not real easy on the skinny pedal though.
 
nvrenuf said:
This is a slippery slope my friend, get that checkbook ready. :D
Click to expand...

I don't have a checkbook, but I do have some pieces of plastic! :rotfl:

Realistically, if I can run it without having it bored, I need to figure out what it'll take to make the 700r4 happy. Nothing is going to happen over night, but I may start collecting parts to make it happen.
 
My 454 got the worst it ever has last weekend, burned around 15 gallons in 150 miles....but, 50 miles of that took 11 hours.
I will post up numbers when I fill it up again this weekend. I generally AVERAGE 12-13 ( driving like I want to get 20 out of it).
 
My last Burb with a 4 inch lift, 4.56 gears, 35's, 468 roller cammed big block, modified factory TBI and 700R4 got around 9mpg in mixed driving and as good as 11 on the road. Sadly , my new mild mannered 383 with Holley Terminator system is doing about the same....:doah:
 
3gal/hr on the trails in 4lo In the Maiden
76CCDRW C30 was best of 9.5 on the hwy empty
 
I know that I could get up to 11 around town with mine, with 462, q-jet,4:56, 700R4 and 33's. I don't drive it hard, but not real easy either. On the highway, I believe it went up to 12.5???? If I kept the speed down.

I have not checked it with the 35's.
I can see how your numbers are probably right.
But the question is, would you be playing with the boost of power, which would negate the fact that it would feel moving easier????
Ask your right foot. ..
 
I get about 13 on the hiway at 65mph. I have an HO454 with injection off a Mercruiser MPI Mag. 35 inch tires, 4.10 gears and a 4L60.
 
My C20 got 8-10 with a stock 454 4.56s and a turbo 400 @80mph. My full roller 468 with aftermarket heads and a crappy edelbrock with my NV4500 in the same truck got 12 in the same truck.
 
Our stock 77 c20 with a rv cammed 454 will get 15mpg on the highway. Usually run down the highway 70-75mph no problem, 3:21 gears do have some advantage!
 
Last edited:
getting about 11 as a DD could probably get a little better if i took the lead out of my shoes was up over 13 when it had 35s but added some weight with the d60 and little more wind drag now with the extra lift to clear the 38s
 
You must log in or register to reply here.

Latest Posts

Top Bottom