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carbed 5.3,ls1

Posted: Sun Mar 03, 2013 12:55 pm
by gnicholson
i've been thinking about taking a 94 s10 i have and install something like an l33 5.3 or ls1 etc for a daily driver.i would use the existing 4l60 with a controller after being rebuilt with a new convertor.i was thinking about using a dual plane with a 4 hole adapter spacer and an 80's q jet,something like an ls6 cam.i want the thing to make good power but i want to err on the side of good part throttle fuel effeciency. i'm think i could pull off 25to 30 mpg with the right setup.would i be better off sticking with the factory truck or camaro vette fuel injection for this setup ?i think the qjet setup would be cool and hard to beat for cost and ease of the swap.opinions appreciated :D

Re: carbed 5.3,ls1

Posted: Sun Mar 03, 2013 1:55 pm
by Eric68
Stick to the fuel injection. There is a pretty significant mileage advantage using fuel injection over a carb in an application like yours. Stick with the factory wiring harness and computer if you can.

Now if your main goal was drag racing then my answer would be different, but you want real high mileage and a quadrajet isn't the way to do it.

Re: carbed 5.3,ls1

Posted: Sun Mar 03, 2013 2:10 pm
by Matt Gruber
bill jones reported 29.9 mpg with a qjet.
I'd keep it simple and avoid efi. I'd maybe try to keep the knock sensor/ecm as best timing is important for max mpg.
i'd use the Holley double pumper 4 1 6 5 - 6 2 1 0
quick response and engineered to sip gas, maybe a tad more than a new qjet, but they don't make qjets anymore, and commercial qjet rebuilds are often a butcher job.

Re: carbed 5.3,ls1

Posted: Sun Mar 03, 2013 2:44 pm
by sanfordandson
a friend of mine has a similar setup and pulls low 30's with efi. definitely stick with efi if efficiency is your goal.

Re: carbed 5.3,ls1

Posted: Sun Mar 03, 2013 2:52 pm
by gnicholson
thanks for the responses.i've built qjets for 30 years and have a good supply of parts and good cores. a good holley would be a good choice to.wy concern with a carb is lack of manifold heat and the engine induction not really designed as a wet fuel system. don't know how good the retrofit carb manifols are on fuel distribution etc.thanks for the above comments.all have valid points.my thing is i drive alot on the highway and i need some mileage with gas prices being insane like they are but i also like driving something that hauls ass when you want

Re: carbed 5.3,ls1

Posted: Sun Mar 03, 2013 9:53 pm
by Auctioneerhere
I have a 5.3 LS engine w/ a 500 CFM 2 jet on it.

It seems to plenty of power.

It was in a demo car, so we never worried about gas mileage.

Re: carbed 5.3,ls1

Posted: Wed Jan 29, 2020 11:33 am
by raynorshine
gnicholson wrote: Sun Mar 03, 2013 12:55 pm i've been thinking about taking a 94 s10 i have and install something like an l33 5.3 or ls1 etc for a daily driver.i would use the existing 4l60 with a controller after being rebuilt with a new convertor.i was thinking about using a dual plane with a 4 hole adapter spacer and an 80's q jet,something like an ls6 cam.i want the thing to make good power but i want to err on the side of good part throttle fuel effeciency. i'm think i could pull off 25to 30 mpg with the right setup.would i be better off sticking with the factory truck or camaro vette fuel injection for this setup ?i think the qjet setup would be cool and hard to beat for cost and ease of the swap.opinions appreciated :D
-did you ever complete this swap? results? =D>