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EFI or carburetor on a 1991 trans am

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Old Mar 28, 2026 | 12:28 PM
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Dazed's Avatar
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EFI or carburetor on a 1991 trans am

So picked up this 91 a few months ago and have been trying to fix it up the 305 needed replacing so I got a 1996 vortec 350 it has the stock Chevy 1500 TBI setup and I would like to know if there's a wiring harness and ECM that could work with mine and I could just run the gauges off the old ECM alternatively I can swap it to a carburetor but it might not clear the OEM hood I want to put on it or I can buy a EFI system with built in ECM. (Pics below)1G2FW23F6ML247424

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Old Mar 29, 2026 | 01:14 AM
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92droptopws6's Avatar
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From: Las Vegas
Car: '88 Trans Am
Engine: 5.7L TPI
Transmission: Slushbox
Axle/Gears: 3.27
Re: EFI or carburetor on a 1991 trans am

I would definitely purchase a vortec tbi intake and put the tbi back on the road
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Old Mar 29, 2026 | 06:43 PM
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Firechicken82's Avatar
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From: CT
Car: 82 TA
Engine: Zz430 clone w a torquestorm blower
Transmission: Magnum f
Axle/Gears: Ford 9 w 4.11
Re: EFI or carburetor on a 1991 trans am

The engine will bolt in/up fine to everything less the intake. The vortech heads require a vortech intake bolt pattern. The intake currently on the engine is pretty high and likely wont fit under your hood. You probably can find an aftermarket intake that will fit a stock tbi and has a vortech bolt pattern. If this isn't an option, some kind of a adaptor plate for the tbi to mount on a vortech intake. Once its all bolted up you'll likely need larger injectors on the tbi plus a custom prom chip.

another option is a stand alone efi system. Think about the price of getting all the tbi parts and if you have access to someone who can help tune it. Is a stand alone efi much more money? There are people on this forum who can do all that tuning/prom stuff. Those tbi systems are totally limited airflow wise. A stand alone efi will absolutely have more power potential if tuned well. Just a thought.
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Old Apr 2, 2026 | 06:30 PM
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From: Armstrong B.C.
Car: 1991 camaro Z28
Engine: Forged 370" LS turbo s488
Transmission: Built 4L80e FTI converter
Axle/Gears: MWC 9" 35 spline 3.25 gears
Re: EFI or carburetor on a 1991 trans am

Go EFI in today's world of plug and play systems carburetors are for the people that can't figure out EFI
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Old Apr 3, 2026 | 12:47 PM
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Re: EFI or carburetor on a 1991 trans am

Yeah I'd say that's me tho I'm 20 trying to fix my car in a driveway so I can gtfo
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Old Apr 3, 2026 | 12:52 PM
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Car: 82 TA
Engine: Zz430 clone w a torquestorm blower
Transmission: Magnum f
Axle/Gears: Ford 9 w 4.11
Re: EFI or carburetor on a 1991 trans am

Originally Posted by Dazed
Yeah I'd say that's me tho I'm 20 trying to fix my car in a driveway so I can gtfo
i did my first efi swap in my moms driveway. And the first manual trans swap, and another trans, then a rear. It was less than ideal to say the least. I was so psyched to have garage later.
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