I have an 1988 Camaro with the 305 5.0L that I would like to convert from TBI to carb. I've read through the tech articles and the threads I could find.

If anyone could answer these questions for me, I'd greatly appreciate it.

1) Will I be able to use the stock hoses for the fuel (to the AFPR, and return line back to the tank)?

2) Does the fuel pump need rewired? If so, how?

3) Can you recommend a specific distributor that I could use (preferably one by MSD) or the specs that one must possess?

4) Can I just get a non-EGR intake manifold and delete the EGR?

5) Is there anything else I'm looking over or haven't thought of yet?

Thanks in advance for the help.

 

https://www.thirdgen.org/carbswap

 

I've already read through that. My questions aren't directly addressed. Hence why I made this thread.

 

Yes

run a wire from key to pump relay

Any non computer controlled SBC distributor with vac advance.HEI from any GM V8 cheapest
See
http://www.summitracing.com/search/P...o/?keyword=msd

Yes

Need some way of turning radiator fans on

 

Great. Thank you for the information. The previous owner already wired the fans to the ignition so that shouldn't be a problem. It seems like a pretty simple, straight forward swap.

 

One needed thing that is not mentioned is the transmission TV cable geometry corrector bracket that mounts on the carb throttle arm. Which one you needs depends upon what carb you get.

 

My car has the five speed manual transmission though, so I wouldn't have that cable, would I? IIRC I have one cable for the throttle and another for the cruise control.

Also, when switching from a computer controlled to a non-computer controlled distributor, wouldn't the wiring for the distributor change? Is there some sort of harness adaptor I would need?

 

Bump. Help please. I need to buy parts so that I can pull her out and get her all fixed up in the spring.

 

The dist will come with a wiring diagram and tell you how to wire it in. I went with the Jegs Street/Strip HEI. It was right at 100 bucks and looks just like a msd.

 

I need more info on this, what if I do not?
I have it priming when I turn the key now, will it not continue to pump?

 

Alright. So what about this setup:

Dizzy: http://www.summitracing.com/parts/MSD-8362/
Carb: http://www.summitracing.com/parts/EDL-1801/
Manifold: http://www.summitracing.com/parts/PFS-52001/
AFPR: http://www.summitracing.com/parts/QFT-30-900/

On a stock 1988 305 5.0L.

 

Distributor is fine.

Carb - expensive for what it is - look at a standard Edelbrock 1406 carb - $100 less, more cfm that will do fine on the 305, and easily feed a 350 later.

Intake - I would take the savings from the carb selection, and put it ito a better intake - look at a Edelbrock Performer RPM - it's what most of us use because it's a great intake.

FPR is fine.

On the fuel pump - the ECM controls the fuel pump. No ECM and the fuel pump won't prime anymore. Not an issue since a carb holds fuel in the bowls (plenty to start and run car for a few minutes). Youe fuel pump will run as soon as the oil pressure sending unit senses oil pressure (a backup built into the system), so the car will start and run fine, unless it's been sitting for a few weeks and the gas in the carb bowls has evaporated down - even then it will still start and run, just takes a few seconds for the OPSU to sense the oil pressure building up from starting and turns your pump on.

BUT - most folks wire the fuel pump relay so that it runs as soon as the key is turned on. It's a simple matter of cutting the wire from ECM to relay, and putting 12v to that wire from a key-on source.

 

Great! I'll take your suggestions into consideration. Thanks for the information!

 

Mechanical secondaries are required for a manual transmission, correct? What is this Edelbrock "air valve" thing? Is that the same as a mechanical secondary?

 

Mechanical secondaries are recommended for manual transmission.

The "air valve" limits air flow when the secondary throttle blades open to prevent bog - it takes a little time for the fuel to work its way through the secondary metering system when the secondaries are opened, and without fuel to go with the air, you get bog. A "double pumper" or "dual squirter" mechanical secondary carb adds extra fuel as the throttle blades open to give you some fuel until the metering system can kick in.

Carter AFB, Edelbrock Performer series, and q-jets all use an "air valve" set-up. Others have used it as well over the years, but those are the carbs you'll likely see in 4 barrel versions these days.

 

So would that air valve system work okay with a manual transmission, or should I look for a double pumper?

 

this thread has also been very helpful to me so thank you element. But i do have the 700r4 so i will need that tvc bracket. now my question is what kind of advantages are going to come with "the correct" Carb set up? from the stock TBI. looking for non biased answers but actually experience with this swap.

 

It will work okay. The only "issue" with the air valve is when you shift while during WOT runs. There will be a slight delay as the air valve closes and reopens. Better than a vacuum secondary carb, for sure.

 

Exactly what I needed to know. Thank you.

Is the vacuum advance distributor okay, or would that have problems with the manual transmission?

 

food for thought - if you're running a 700r4 w/o the computer, you need to get a kit to allow the TC to lockup. there are DIY guides kicking around the transmission subforum or you can buy a kit from jegs/summit

 

You need a distributor with mechanical and vacuum advance when not using a computer controlled system. The vacuum advance is not affected like a vacuum secondary carb is.

 

so what about the transmission if i ran my 91 rs 305 carb and ripped out the ecm how would my tranny know when to shift?

 

Thinking of doing this myself. Tbi to Carb. Great info so far.

 

Tranny will shift fine - the TV Cable determines shifting. You'll need a TV Cable Geometry corrector ($20) for your carb linkage. The only thing about the tranny controlled by the ECM is the torque converter (TCC) lockup - you'll need a method of locking it - either wiring a switch, or using a kit that goes into the trannny - there's a sticky on the carb section about TCC Lockup.

 

saving info

 

Thanks for all this information! im about to do this swap myself tomorrow