351w engine build bullnose
 

Ok so I have a 83 bronco 351w 2bbl carb with duraspark II.
I am doing a mild performance build including 351HO intake 4bbl, Holley 4bbl 600cfm carb, gt40 heads, comp cam, and headers.

So I am porting the intake to be at least closer to the gt40 heads.

Questions:

Will the original egr valve work on the HO intake?
What smog crap can I delete hopefully the pump, and other stuff.
The O2 sensor can it be located lower for the headers and no cats?
What is the O2 sensor for on a carved engine?
What is the valve deal on the drivers side exhaust manifold and can it be deleted?

Will the duraspark II work fine with a mild build or should I do a MSD 6a swap?

Will the electric choke on the new Holley work and hook up the same as the original 2bbl Holley electric choke?

I don't have smog to pass so that is easier.
This is my first carb vehicle build I have only rebuilt the carb on my Harley.
Trav

If you want to get rid of the "smog crap", then don't worry about the EGR, just block it off with a piece of metal if it's made into the intake, or just get a different solid spacer if it's part if the 4bbl spacer assembly.

If you have a O2 sensor, then your truck was not originally duraspark II, it had a computer on it with a different distributor or a different engine was installed and the old exhaust manifolds with the sensor were re-used. Are you sure you have duraspark II? Do you have a vacuum line going to the distributor?

The valve deal on the exhaust manifold is the heat riser. When the engine is cold, it blocks the exhaust from going out, and forces it back up and underneath a passage under the carb to help the intake and carb warm up. Once it warms up the heat riser opens and lets the exhaust through normally. If it works I would keep it. If it doesn't and you want to get rid of it, you will have to keep it and gut it out and seal it up, or you will have to get another exhaust manifold that does not use the heat riser. They make them, and you will need one if you want to take the valve completely out.

Duraspark II will work ok for a mild build. You may have to buy a adjustable vacuum advance for it for the final tuning.

The holley electric choke takes 12v, the original electric assist choke was only 7v. You can try it and see if it works, it may be slower but still work, I have never had a holley electric I always buy manual choke Holleys.

See below in red.

On the DSII question, I don't see why it wouldn't long as the RPM range of the engine will remain fairly much in the stock ranges.

I planned on reusing as much OEM for my engine build. Still don't know if I will do a mild build of a roller 302 or build a 332 or 347 stroker. Either way I go I will be omitting the air injection pump (don't have converters at this point so the air pump serves no purpose. I would leave it on if it wasn't for the back fire in the exhaust I get if I let off the throttle quickly around 2500+ rpm) but the EGR I am leaning towards keeping. My only goal is to build a 302 that will be reliable and function with the oem induction and ignition system. Aside from that I only want to get this engine to make 250 to 300 hp and I'm happy. Way better than this engine now that I bet is lucky to make 120 hp.

Re: the two questions Gary didn't reply to.

Yes, a DSII ignition is fine for your engine combo but you might want to recurve the distributor.
Instructions can be found on RHP's website.

http://www.reincarnation-automotive....ons_index.html
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Aftermarket Holley's use a 12V choke cap with an added ground.
If you want to keep the stock stator wiring you can simply swap the old 2 barrel carb's choke cap onto the new carb. (Edited for clarity)

Thanks, Jim. I missed those.

Translation: 2V means 2 Venturi aka 2bbl. ;)

Ok so you are right I have a computer not duraspark II. I am guessing because no vacuum spot on the distributor. I was going off my cousins word that it was duraspark II I know very little about carb engines having my dad and buddy who builds race engines help me.


So do I keep the computer set up or swap to duraspark II or another ignition? Which would be best?
I am just trying to get a build of a weekend warrior/cruiser build that is show quality but off roadable.

I am willing to keep the emissions stuff if I have to was planning on keeping the egr if it would fit the 4bbl intake.

On the heat riser since I am installing headers won't that delete it? Also running true duals exiting before the tire currently and will afterwards also.
Trav

EGR comes from the factory 4bbl H.O. intake into the egr spacer beneath the carb.

If you chose an aftermarket non-EGR intake then you just use a regular spacer.

​​​​​​​If you have a computer controlled TFI ignition now and intend to get rid of the carb, O2 sensor, etc.. you have a choice of going to DuraSpark II, using a DSII distributor and some other (MSD style) ignition, or getting an 'all in one' HEI distributor.

Yep, Edelbrock sells their intakes with EGR and without. If you buy theirs with EGR you have to be careful cause they send the 2V EGR adapter plate but they sell a 4V EGR spacer plate separate for their intake manifolds.

Personally, I'd go non-EGR. But, as I said earlier, you should re-curve the distributor if you do eliminate EGR. So, you may decide it will be easier to keep the EGR.

He can't use his TFI distributor anyway...

Screw it, ship it to me and ill drop a 5.0 Coyote under the hood for you lol.

Question does the trick on the fuel injection trucks look the same as the trick on the carb this?

One pic of the intake I am putting on, the ignition box on the bronco, the engine as a whole and the egr on the intake on my bronco now.

What would be the best and most simplest ignition system to install. I will either fit the egr to the 4bbl carb or delete it either way whichever is simpler and better.i would be happier without the O2 sensor no real reason. Just want a simple non computer everything truck unlike my 88 just so I have one of each.
Trav

that sure doesn't look like a carb intake. Looks more like a tbi or maybe a feedback carb setup.

Hmmm

You DO have a duraspark module but the distributor plug is not connected to anything.

If you don't have that harness for the distributor and coil then the simplest thing to do would be an HEI style distributor.
​​​​​​​It handles all ignition duties and only needs a relay controlled source of key on power.