Long story short, I'll be running a carb on my 383.

Edelbrock dual plane RPM Air Gap manifold with a Barry Grant Speed Demon 850 cfm carb.

What kind of adjustments will be required when hooking up what's left of my computer to it? Will the dash cluster need to be swapped out or will it still function?

Also, I had a 255 Lph Walbro in tank fuel pump running previously at like 45 psi or so with a LPE Super Ram and LPE 58 mm tb. So, can I just regulate the psi down to the 7 or 8 psi or do I need a new fuel pump?

 

I did a carb conversion on my 84 and there are some differences on what the ECM controls on later models llike yours. The only things I lost were the miles per gallon function and the TCC lock up for the trans. You can buy an aftermarket lock up kit from Jegs our Summit to fix this. There may be some other functions that you need to address also with your 89. I would highly suggest that you run a 1/2" carb heat insulator, plastic or wood, under your carb as the heat in the engine compartment will tend to boil the gas in your carb after driving the car and then letting it set for 10 minutes or so. I used the 1/2" plastic resin spacer and between that and my hood scoop my engine temps have dropped quite a bit. As far as a fuel pump goes you can probably use your 45 psi pump and a good fuel pressure regulator like the Mallory 4309 which has the return line port. You can also install an intank pump from a GM car that had a carb and an intank fuel pump and around 6 lbs. psi. Or you can eliminate the intank pump and install some type of inline electric pump-I use the old Carter 4070 puimp in two of my vehicles with no problems supporting 400 hp.

 

You'll need a conventional distributor too.

When all is said and done, you will likely have hood clearance problems. I put a scoop on my '86 and it turned out really nice, with no cracking at all.

Let me know if you need help with that.

 

Switch to an 84 pump and use a bypass regulator. A carb regulator that isn't north of $300 won't be able to bypass that much fuel from the stock pump. That's what I did and I've had zero issues. Other than that, I think everything else is covered. I'm running a 2 1/4" cowl CF hood from Toledo Pro that has no undertray so I have no clearance issues with my Race Demon 750. Also using the Spectre cowl induction filter assembly.

I will add that I completely rewired my entire car, as it's track only. Nothing is stock wiring-wise. I'm running an MSD 6AL and an MSD Billet distributor with a Blaster 2 coil.

 

Good point on the FPR and using a 84 15psi pump. The Mallory 4309 is around $100 and a quality unit. I used a new Accel HEI distributor that I bought off fleabay for $70 but any SBC or BBC point dist. or 75-80 pre computer HEI will work. I did rewire my fuel pump circuit bypassing the stock oil pressure switch. I pull 12V from the back of the alternator and run that to my relay power in and the power out side of the relay to a 12 gauge wire back to the fuel pump. I use a 12v ignition switched source to trigger the relay. The fuel pump now turns on when the ignition comes on and I also added a Ford inertia switch in the circuit to shut the pump off in case of a crash.

 

I beleive that Aeromotive makes a bypass regulator that will accept EFI type input pressure and output 6 - 8 psi, but it's not cheap.

 

If you leave rhe OP switch in place you dont need the relay.Pump will run as soon as engine cranked over and stop running as soon as engine. stops.Key on prime function not needed on a carb engine

 

You can't get an air gap intake under a stock hood, but you can get a performer EPS to clear.

Aero motive sells a carb regulator purpose made for a conversion from stock FI to carb. AED sells a bracket to told it and a fuel pressure gage.

On my 84 383 conversion, I use a VetteAide analog dash replacement with Autometer gauges. The provide all new sensors and wiring diagrams, although it is a 6 gauge plug and play application. 2 to 3 hour install

 

What all is going in your 383 component wise?

A Holley HP 750 or AED 750 will be plenty to feed that in most cases.

 

Scat Crank and Rods, Keith Black Hypereutetic pistons, Patriot 190 heads, Performance Distributer DUI HEI ignition, Edelbrock Performer EPS intake (2101 I think)! AED prepped Holley 750 double pumper(flows 820 cfm), Aeromotive fuel regulator and stock in tank fuel pump with return line upgraded to -8 AN.

I am using the stock 2 bolt block with ARP main studs, Milodon high volume oil pump, Moroso 7 quart stroker oil pan and wind age tray.

Dynos 460hp and 475ftlbs with a 10:1 CR

Heads have 64cc combustion chambers and block decked to 9.0

Cam is a Comp Cams custom grind 269/269 with a duration of 226 for each lobe at .050 106 LSA in at 4 degrees advanced (grind number 5444/5444)

 

'84 w/ 700r4. Ditched the ceasefire for a holley 650 CFM and dual plane manifold.

Kinda had to do some custom engineering, making some custom brackets, as the throttle cable is so long and the kick down cable only goes to one side. Essentially mounted the carb backwards (primaries towards firewall). Also went vacuum HEI distributor. Good luck!

 

I used a HEI vacuum distributor too. Pretty simple without a lot of hacking. I actually converted my 84 back to a superram after a couple years of carbing. As mentioned, gauges still work except for mpg.

 

I read all the same things you are going through. I have just finished by 383 build, I had the Mallory fuel pressure reg….all in all to make a long story short the issue is the return line size. Here is what I did and wish I would have done this from jump street.
1. holly red fuel pump.
--I mounted to the bumper reinforcement were the lice lamp is mounted made a bracket to hold it.
2. get the braded line kit from summit and the dual fee holly line.
-1 line from the stock fuel sending rand down the rear face of the tank (b/t the bumper and tank
-90 deg to pump
-stright out of the pump to the line ran in place of old line.
-inline filter were the old one was.
-line to the dual fee straight fitting no issue.
3. fuel pressure regulator into the tee
4. pull the sending unit, take the pump off, I put a pice of hose in place of the pump and put the screen from the pump on the hose and ready to go.
5. got a spare sending unit so I used the old pig tail off of it to clean up the wiring.

-the red pump cost about the same as the regulator
-the old fuel lines and fittings are a pain in the *** to match up to anything (biggest head ache)
plus now you do not have to worry about corroded lines possibly busting
-I hope this helps you, it took up too much of my time messing with this part.

 

On my 84 carb conversion I used the stock throttle cable and the stock TV cable with no problems. I ordered the brackets I needed from Summit and Jegs.