Has anybody made this swap ? 305 TBI to a 350 TBI ? I know the stock 305 TBI unit could not feed this motor, but I have seen some good options, like Turbocity.com. Anyway can anybody lend me some help, thanks.

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1990 RS Camaro 305 TBI
700R4 Tranny
3" cat back system with flowmaster mufler
Edelbrock strut brace tower and rear panhard bar
Spohn subframe conectors and lower control arms
all polyurithene bushing under the car
March underdrive pully
K&N filter
Hypertech chip
Aluminum driveshaft
3.42 posi rearend
Killer sound system
Many new mods to come

 

umm find a guy named firbird on these boards......he just swapped in a 350, not sure if it was zz4...i think it was dont hold me to it......but he has the holley TBI unit and *gasp* edelborck TES's.....his bro just gave him a 87 firebird to go along with his 92...not sure which he put the engine in...anyways he finally got it up and running......(open headered though) talk too him he's sure to have some advice.... if you scroll down you might see his post about his new tbi

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1991 RS LO3

some of my favorite quotes:

I do not blame stupid people for being stupid, what i do blame them for is for not asking smart people for advice. When ever my mom asks for help, i tell her, i'm the one who knows what he's doing, not you, don't question me, just do what i tell you to. if stupid people would just realize they were stupid, and consult a smart person for advice, before they went and did something stupid and got pregnant/got someone pregant, this ****hole of a world would be a lot better. - adam corola

Honda makes great performance cars - any scarcastic comedian

 

i dont have the zz4 but i do have the other cheeper 330hp one with vortec heads. DM91RS, jprevost have 350 tbi those are just some people who i can think off my head. like budman said i have a holley tbi and right now i am just trying to get a few kinks out of my engine.

 

What intake did you use, stock or the edelbrock ? Did the Holly TBI unit hook-up without any problems ? thanks for the help.


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1990 RS Camaro 305 TBI
700R4 Tranny
3" cat back system with flowmaster mufler
Edelbrock strut brace tower and rear panhard bar
Spohn subframe conectors and lower control arms
all polyurithene bushing under the car
March underdrive pully
K&N filter
Hypertech chip
Aluminum driveshaft
3.42 posi rearend
Killer sound system
Many new mods to come

 

The holley 2" (670cfm) unit won't bolt onto the edelbrock TBI intake. You're better off getting an adaptor plate and using a carb intake. Be careful though, with the RPM intake you won't have any hood clearance.

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, Jon (350 TBI!)
91 Red My website

 

I just went for a 25 mile test drive with chip burn #12 and it pulled great to 5800\6000 rpm through 3rd gear. No knock counts, did not do plug check. But, this is with stock tbi with stock 55lb. injectors set at 10psi. I have had nothing but trouble with the 670 Holley unit that I purchased and would not recommend one. I had trouble with the injector spray pattern, the fuel pressure varying and the throttle sticking open at 1500 to 2000 rpm. I changed the injectors to the GM pod and this improved everything except the sticking even with 2 added return springs. The GM unit will go a long way before needing the additional airflow of the larger unit. If I would do it again and went with a bigger unit I would go with the big block GM unit.

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91 RS 350TBI..... Vortec heads..... Holley 670..... Edel. intake .... Lt4 cam 1.6 rollers ..... Edel. TES headers .. 3" exhaust ..... 5spd 3.08

 

first.

the 305 and the 350 tbi are the same.

the small block tbi will work on the zz4, it will just need a good manifold and larger injectors. ie. 68pph.

a larger throttle body on an application like that would be better though. but not absolutely needed to drive it. race it, get a bigger tbi.

 

I am wanting to replace my 305 and am trying to find out all of my options. I have thought about going to a TPI setup, but it would cost much more.

1. Would I need to change the wiring harness or computer to go from a 305 TBI to a 350 TBI (like the ZZ4) ? I realize that I will want to get a custom chip.
2. What intake do you guys suggest and can I stay emmisions legal ?
3. What headers work best with the TBI ?
4. Any other advice you may want to give me, by the way this is going to be drive a lot, so I am looking at a high compression 400+ horsepower motor. Just wan't something fun to drive on the street, highway, and occasional race. Thanks for the help.


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1990 RS Camaro 305 TBI
700R4 Tranny
3" cat back system with flowmaster mufler
Edelbrock strut brace tower and rear panhard bar
Spohn subframe conectors and lower control arms
all polyurithene bushing under the car
March underdrive pully
K&N filter
Hypertech chip
Aluminum driveshaft
3.42 posi rearend
Killer sound system
Many new mods to come

 

like JPrevost said there is nooooo clearance under the hood (with the rpm) i had to jack up the back part of the hood and got a little foam air cleaner to make it fit. The wiring harness works it is just the same and the headers many of them out there its just based on how much you want to pay for them but you do get what you pay for.

[This message has been edited by firbird (edited August 04, 2001).]

 

Ok, It sounds like I will try the ZZ4 crate motor, but I do have some more questions.

If I use the Holly 670 TBI, does it plug into the factory wires ?
Would a 454 TBI unit also work for this application and how big is a 454 TBI unit ? 2" bore ? 600 CFM ?
Would a single 3" catback with flowmaster be enough for this motor or should I go with a dual catback system ?

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1990 RS Camaro 305 TBI
700R4 Tranny
3" cat back system with flowmaster mufler
Edelbrock strut brace tower and rear panhard bar
Spohn subframe conectors and lower control arms
all polyurithene bushing under the car
March underdrive pully
K&N filter
Hypertech chip
Aluminum driveshaft
3.42 posi rearend
Killer sound system
Many new mods to come

 

The stock 454 throttle body has a different IAC plug, and it doesnt have a connector for the TV cable. But it is 2" and 670 cfm.

The ZZ4 engine wont pass smog because the heads dont have EGR, if that is a concern.

A 3" catback is fine, thats what we all use.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
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