I'm looking to swap out my TBI for a carbeurator. I've had more problems with the electronic/computer stuff and I'm just giving up on it. What should be done to do this swap, I'd like to keep the in-tank electric fuel pump and just regulate the pressure down to the acceptable level. Since I already have the return lines could I use a return line style AFPR and run the stock return line to the regulator? Comments and suggestions welcome.
BTW, if I decide to do this I'll have a Holley 670 TBI, a Holley TBI to 4bbl adaptor, a Pocket Programmer PROM burner, and a PROM eraser for sale, just drop me an e-mail and make me an offer.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

I found the tech article on this subject and so now I have a new question. Could you leave the OEM distributor on there and just let the ECU control it? This way, the only thing that you would change would be the fuel control, so you would still get torque convertor lock-up and such.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

I dont really know if this will help but i done a engine swap from a 305 tbi to a carborated 408 small block . I still use the in tank fuel pump but instead of a regulator I also use a mechanical street carter fuel pump on the motor.as for your question on if your torque converter, will it lock up I don't really know?I don't think it will. I grenaded mine on the test drive for my new motor so I never got to find out for sure.I do know i had to change my distributor to a old HEI distributor to get it to work right.Hope I help some.

 

Neither the distributor nor the lock-up will work if the ECM does not detect the OEM stuff (ie: the TBI). You will need to get a vacuum advance dist. and wire in a switch to manually control lock-up or buy a lock-up kit from aftermarkets.

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George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB
Chevy Info --> MadMike's

 

Mrz28HO is right. You will need a vacuum HEI. You will also lose your computers ability to lock up the converter, but there are vacuum switches available to solve that too. Or a manual switch, but you have to remember to turn it on...

You will need a new intake manifold. If emmissions are a concern, get an Edelbrock Performer manifold. No e-check, get the RPM or a Weiland.

Auto = vacuum secondaries, manual= mechanical secondaries. Electric choke is a good thing too. Size engine? A 305 would go good with a 625cfm carb (I'm thinking Road Demon), but a 350 will need a bigger carb... like a 750cfm.

I am swapping a Holley onto where my q-jet used to sit and I am finding MANY little things like the throttle bracket doesn't have the little studs to attach the cables to ($7 ea), I need a new cable bracket to hold the TV and throttle cables to the manifold ($15 and on backorder), the fuel line that came with the carb (dual bowl) hits the EGR valve, vacuum hose re-routing, fuel line fittings, etc..

I run a Carter Street pump and it will run through your intank pump. Going from 14psi back down to 6psi can be done, but a pump is cheaper then a regulator...

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

-=ICON Motorsports=-

 

I did the swap a few weeks ago, used the intank pump and lines and mallory regulator set at 4.5 psi on a carter 600cfm carb, performer intake non egr. switched to MSD ignition and distributor. Expensive, absolutely, but preferred the MSD. HEI will be LOTS cheaper to do.

Went to the dyno today here's the results.Sorry, I know this isnt a brag board but thought some might interested in this.

Today's Dyno Run 5 1/4* advanced timing.
Top Speed = 170.3 @ 3800 RPM
5th gear 38.52 seconds.
Top HP = 188.6 @ 5500 RPM 4th gear.
Top Torq = 333.2 @ 5500 RPM 4th gear.
Eng HP est= 230.3 @ 5500 RPM 4th gear.
Current engine setup;
Open Element, K&N filter
Carter600cfm w/ 750 jets
Performer Intake
1.6:1 Magnun Roller Rockers
Hooker Shortie Headers
2 1/2 exhaust, hollow CAT, full boar muffler
Under drive pulley kit
Aluminum driveshaft
3.42 Limited slip rear gear

Dyno run done at PowerHouse Performance, MidWest City, OK

 

Actually, contrary to the naysayers here, you can use your computer and stock distributor as stand-alone pieces. I don't know the details, this is a topic for the PROM board. But i do know for a fact that you can hack your 'puter to run just what you want.
...ed