Carborator to throttle body - Second Generation Pontiac Firebird (1970 - 1981) - Firebird Nation

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Carborator to throttle body


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9 replies to this topic

#1 Laybacklenny

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Posted 05 May 2020 - 07:36 AM

Not sure i'm in the right forum but here goes. I am considering switching my 1974 350 four bolt from carb to throttle body, Anybody do this .

I have all the parts from a 1989 ? ( not exactly sure of the year)  Chev pickup. Can i do this or will i be sorry if i do is it worth the trouble?

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#2 sea dog

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Posted 05 May 2020 - 10:55 AM

Your 1st obstacle is that your 89 chevy pickup pump and sending unit assembly would not fit your firebird gas tank. Also gas tank from 89 would not fit firebird. Then, your 84 firbird is not wired for an electric fuel pump. The fp wiring system involves the engine computer to work correctly.

 

My advice, if you absolutely have to have tbi injection, is to find a88-92 firebird with tbi that's being parted out. Then you will have everything you need to make the conversion. Or better yet, just buy a firebird already equipped with tbi system. 

 

Last recommendition would be to buy a new carb, if that is what is wrong with car.



#3 JoePeek

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Posted 05 May 2020 - 12:02 PM

One more option would be to get an aftermarket EFI system from FAST, Holley, and there are others. I would not recommend getting one that is self learning, you need to be able to tune it. I got one from FAST and after you get familiar with the XFI software it's a lot like tuning a carb, but with a laptop, and you don't need to open the hood. It will also datalog, so you can review the wideband O2 data and dial in the fuel curve. Idle, WOT, transition (as in  accelerator pump shot), cold engine enrichment, and other things.


Edited by JoePeek, 05 May 2020 - 12:10 PM.


#4 Laybacklenny

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Posted 06 May 2020 - 06:11 AM

 I should explain sorry, here is what i have   https://s824.photobu...sewife/library/  1954 Chevrolet Panel Truck

Built from the remains of three 79 to 81 Firebirds/Camaros .I thought I would use an external pump and do the wiring with a little help.

I am up for the challenge but if you guy's think i'm wasting my time I will drop it. Was hoping someone may have already done this. Guess I am testing the waters on the whole idea. Thanks for the input.

 

Laybacklenny



#5 Injuneer

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Posted 06 May 2020 - 06:26 AM

I must be slow, ‘cause it’s still not clear to me.... you have a 1974 Pontiac 350 that you put in a 1954 Chevy panel truck, and you want to swap the Pontiac carb out for the throttle body injection system from what may be a 1989 Chevy pickup.  Not sure what parts you are using from “79 to 81 Firebirds/Camaros”. What engine did the TBI come off of?


1994 FIREBIRD FORMULA
FRED

 
381ci all-forged stroker (Callies Stealth, Oliver billet rods, BME 2618-T61 nitrous pistons) - 10.8:1 - CNC LT4 heads/intake - Comp Cams solid roller - MoTeC M48 Pro engine management - 8 LS1 coils - 58mm TB - 74#/HR injectors - 300-shot dry nitrous - TH400 - Gear Vendors 0.78:1 O/D - Strange 12-bolt - 4.11 Pro-Street gears - AS&M headers - true duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP / 800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117 MPH straight motor
 
https://www.firebird...9_698_32777.jpg

 


#6 sea dog

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Posted 06 May 2020 - 06:41 AM

I think a better idea for a swap would be an ls based Chevy, or GMC truck engine. Either the 5.3 or the 6.0.  Both of these are plentiful & cheap at salvage yards, or private parties parting them out.

 

You could get the whole setup, engine, trans, eng/trans wiring harness & computer, plus anything else you need. A high pressure external fuel pump would do the job.

 

In the end you'll have a modern eng/trans combo with much more horse power & torque than the old 350 with tbi. A sbbc 350 with tbi usually had around 160 hp. The 5.3 ls series had 275 hp While the 6.0 had 300 hp and up.

 

A friend of mine did the 350 carb conversion on a 48 Dodge truck. It involved much work. Doing the tbi on the 350 sbc entered his mind. But the rewards were not worth the effort to him.



#7 Laybacklenny

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Posted 06 May 2020 - 07:10 AM

Yes Administrator you have it right . The front clip and rearend and transmission are from the Firebird/Camaro's , the engine is a 1974 350 don't know what it came from. .The Tbi setup is from a confirmed 1989 Chev Pickup.The reason I am going this way is because it's all there free, just go get it. The whole thing behind this is where I live the  most easterly point in North America, St.john 's Newfoundland Canada . The weather is mostly cold and damp and I would love to get rid of the choke issues,

Appreciate your patience .

Laybacklenny



#8 Injuneer

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Posted 06 May 2020 - 08:22 AM

Makes a big difference whether the engine came from a 2nd Gen Pontiac or Camaro.  Post a picture of the engine.



#9 tjs

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Posted 06 May 2020 - 02:44 PM

It sounds like it a 350 Chevy engine!Pontiac never built a 4 bolt pontiac 350.Tom



#10 Laybacklenny

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Posted 07 May 2020 - 10:16 AM

Unable to post a pic the engine is Chevrolet 350 ... 1974  I believe it came from a van style camper






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