New to the forum. My swap is a 2000 GMC Sonoma (SCSB) with a 5.3 (L33), Brawler 650CFM Double Pumper, MSD 6014, Truck Norris Cam, Single Plane intake, 4L60E, trailblazer 2200RPM Stall, 3.73 gear. Shreds the tires pretty good.

Wondering what type of gas mileage you all are getting running carburetors on your LS'? (Ideally cammed LS'). Not really concerned about MPGs just curious. I'm running a 10 gallon fuel cell so more concerned about range.

Thanks!

 

Thats a fairly specific setup, those 3.73s and the single plane intake will hurt more than anything but I would say you should be around 16-18mpg combined driving under NORMAL driving conditions. Im sure if you drive on flat ground and keep the speed way down it could be better?
A dual plane intake would pick up quite a bit of torque.

Only real way is gonna be to run a tank through it and check actual miles driven divided by gallons burned of course.

 

bigger fuel cell and dont worry about it........

 

Thanks for the replies! I'd be thrilled to get anything over 15mpgs, whenever I do a test I'll post the results. I'm sure a dual plane and a vac secondary carb would go a long way, but i'm a sucker for the look of a single plane. More so just curious what other folks are getting for MPGs with their carburated setups.

 

I have an LM7, Summit Ghost cam, Brawler 650DP, Performer RPM, etc. While I haven't checked mileage, my carb was very rich out of the box with stock specs.

I went down 2 sizes on primary jets and 2 sizes on IFR.s to get a reasonable fuel curve using an AFR gauge. My idle screws are out 1/2 turn. Just some data points for you in chasing mileage!

The car now runs great.

 

I have a stock shortblock L33 with Summit's 218/227 cam, Dual plane Edelbrock and Quadrajet carb, 5 spd Richmond in early Camaro, I get abouty 23-24 mpg, when I'm cruising. My AFR gauge is pegging at 18 on the highway, goes right to 12 when I step on it. Best of both worlds.

 

Wow 23-24 MPGs, thats aweosme. Defintley need to get an AFR gauge on my swap.

 

That's terrific. What model Q-Jet?

 

it's a 17087118 (1987 carbureted F-body 305). Non electronic but dual capacity accelerator pump that I cancelled. It's a dual main air bleed 750. I've tweaked quite of few of them over the years with all kind of recipes I learned from others and some I developed, and this one runs quite well I must say. I'll try to post a video where I'm cruising down the highway and we can see the AFR gauge, along with other gauges. It's on my phone so it me be tough (for me, LOL) to bring it here.

 

from left to right, the gauges are: fuel pressure, water temp, vacuum, wideband, oil pressure.

 

 

Cammed, DP carb, 3,73s, don't expect much.

I'm under 10...mostly a right foot issue.