Don't retap the threads in the exhaust manifold for the two long bolts. Drill them out slightly oversize and use grade 8 bolts with nuts and washers. Just clamp it tight to the intake.

I recommend picking up the special O2 sensor socket to remove the O2 sensor. Once you get it out and are going to replace it, be sure to use anti-seize on the threads of the new sensor.

You might want to consider a "stealth" HEI install. You can leave the lean burn computer housing in place but gut the innards and use it as a place to mount the HEI components. You can then use the factory wiring to hook the HEI ignition up. If you get really sneaky you can take the dual-pickup lean burn distributor and turn it into a functional standard electronic ignition distributor by swapping the guts in from a normal EI distributor and adding a vacuum advance pod. The extra pickup lead can be hot glued to the outside of the distributor as a dummy lead. If you are creative enough you can leave all the original emissions gear in place and mostly intact but disabled to pass visual inspections.

Normally I don't recommend disabling emissions equipment but your truck will actually run cleaner and get better performance and fuel economy with a standard carburetor and electronic ignition than with the lean-burn system.

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Casually looking for a Clifford hyperpak intake for cheap.

That won't work. The "emissions map" shows only the vacuum hoses, not the wiring and sensors. There may be a small "O2S" or "OXS" notation on the border of the diagram. If the O2S is present and hooked up, then it's supposed to be there, and there's no second-guessing that by looking at the vacuum diagram.

I respectfully submit that if you misunderstand this basic point and think there's such a system as "Clean Burn" then you probably ought to do more listening and learning in this thread than talking and teaching.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Any reason for not retapping the threads for the exhaust manifold?

Where can you pick up the sensor socket?

We briefly talked about the sealth HEI install in another thread before. I thought about it but how am I supposed to get around using the Holley 6145 feedback carb?

I'm with you on it running cleaner and better without Lean Burn, but I don't know if the Lean Burn computer is even going to be a problem as far as passing testing. The truck was smogged in 09 and when I got it, it had a vacuum leak and exhaust leaks from the manifold, head pipe, andthe cat converter weld. So far I have 3 of the 4 problems corrected and I'm working on the manifold leak as we speak.

Many people choose to drill out the bolt holes in the exhaust manifold to avoid having the two outboard bolts thread into the exhuast manifold. Instead, the holes in the exhaust manifold are drilled out big enough to allow a long bolt to pass through the manifold (without threading) and a nut and washer are threaded onto the bolts on the bottom of the exhaust manifold to clamp the exhaust manifold to the intake manifold. This method still seals the exhaust manifold to intake manifold junction but eliminates the problem of those two outboard bolts seizing in the exhaust manifold and breaking when they are loosened. Someone out there must have a picture of this done on a slant.

The special O2 sensor socket is available where tools are sold. I got lucky. A mechanic at a dealership left the socket under the hood of my sister's car and the dealership closed before I could return it. It should be hardened like air impact wrench sockets but have a slot up the side to pass over the sensor wire and have an offset mount for the socket wrench extension, like a crow's foot socket attachment.

The Holley 6145 is very similar externally to the Holley 1945. it would take someone who really knows slant six carburetors to see the difference. The main difference between the Holley 1945 and Holley 6145 is the extra set of wires going to the mixture-control stepper motor inside the Holley 6145 carb. The Holley 1945 won't have the plug for these wires, but you could tuck them under there. Plus, the carb is tucked under the air cleaner and is hard to see. I bet you could even swap a Holley 1945 on there and get away with it. I guess it will depend on how thorough the emissions equipment inspection is.

With regards to the catalytic converter, I recommend you at least replace it with a new high-flow converter. Carbs and cats don't mix well since carbs have a tendency to allow too much fuel through the system which leads to catalytic converter overheating and meltdown. Several years ago I worked on my brother's 225 powered 1983 Dodge van in order to get it to pass its last emissions test. I reinstalled the AIR/smog pump and installed a new high-flow catalytic converter. Several months after the van passed the test (with flying colors) there was a horrible rattling noise form the exhaust and the engine performance was way down. I tracked the problem down to the catalytic converter having a total meltdown and the honeycomb catalyst melting and falling apart and being blown back into the muffler and clogging the exhaust line. I strongly suggest you install a new high-flow muffler and a new high-flow catalytic converter, or hollowing out the original converter and reinstalling it.

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Casually looking for a Clifford hyperpak intake for cheap.

Nice, as long as it seals then I'm glad to not have to do any threading. I've already got it drilled so now I just have to work on getting the manifold surfaces flat.

I thought about going to a 1945 but I'll see how the test goes with the 6145 first. I sent one of my ex coworkers an email about testing. He used to be a smog tech at a dealership so I don't know if he knows about older vehicles. He might be able to tell me if the visual inspection is just a quick once over or if there are step by step procedures for checking to see if everything is connected correctly.

There was a rattle and its probably the cat like you said. I'm hoping it was from the exhaust leak but chances are it'll be the cat. I'll let you know if I'm still hearing that when I get everything back together as well.

It is very tough to sneak changes past smog techs in CA. They don't gaze uncomprehendingly at stickers under the hood and say "Uhhhh...gyosh, I donno...I guess you probly have all the stuff on here yer asposeda". They have a database that specifies in great detail what's supposed to be on the vehicle, down to the carburetor type (and ignition timing setting, and just about everything else short of the color of the windshield washer fluid in the tank ), and while it's always possible you'll get a lazy smog tech who doesn't check as long as everything looks like it hasn't been hacked, it's a shame to spend money and effort and time changing things only to flunk smog because you didn't luck into a lazy tech.

Reed's comments on catalytic converters are smack on the money. Leaving aside the dodgy* nature of feedback carburetor systems as a class, they are the only ones that get along passably well with catalytic converters. Deleting the O2 sensor is generally not a move in a productive direction in a situation like yours.

*-Hah! Dodgy! See what I did there?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Sneaky sneaky Dan.

I agree with Dan. While I have never had to submit to a California emissions inspection, everything I have ever heard about them indicates that they are very thorough and strict. This is why I was recommending a "stealth" HEI installation. You can get a wiring diagram for your truck and use the factory connector to the lean-burn computer as the wiring for an HEI conversion with the HEI unit mounted in the lean-burn housing. You can use the guts from a non-lean-burn electronic ignition distributor in a lean-burn distributor housing and just keep the extra pickup leads glued to the side of the distributor and plugged into the wiring harness. The only giveaway would be the vacuum advance pod on the distributor.

The 1945 carburetor is VERY similar to the 6145. Again, the biggest giveaway would be the lack of the plug on the carburetor, but you might be able to get creative with a drill and some epoxy and make it look like the wires were going into the carb but have the wire just be glued in place.

Finally, the HEI system is so compact and simple that it really wouldn't be that hard to leave the entire lean burn system in place but run a standard carburetor and electronic ignition distributor except for testing day.

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Casually looking for a Clifford hyperpak intake for cheap.

It's not either/or. You can do the HEI upgrade as Reed describes and leave the feedback mixture control intact and functional.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

This is true. Everything I have seen and read indicates that the timing controls and the carburetor controls in the lean-burn systems are separate. You can disable one without disabling the other.

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Casually looking for a Clifford hyperpak intake for cheap.

Well I'll probably be sending you that manifold at some point. I just cannot get the original manifold with the O2 sensor to work. Not only are my holes slightly off but the back side of the choke pocket hits the intake and kind of cocks it sideways to the point where the face of the runners are way off. I even ground down some of the loose casting but the intake runner just butts up right against that choke pocket and causes it to be misaligned. I tried my better quality alum intake thats cast better and it doesn't work either.

I grabbed the 64 manifold and my good alum intake and made a gasket out of nice composite gasket material to go inbetween the two manifolds. After some tightening up, the runners are pretty darn close. I'd say an hour of blocking out the end of the runners with my long block and it should be ready to try and bolt on. I'm going to have to try Ceej's suggestion and see if the muffler shop can install the O2 sensor right there in the headpipe.

Edit - Ugh I just called a couple smog shops and they aren't sure if installing the O2 sensor in the head pipe will pass smog. They said it would have to go to a referee and they would probably make me try and find another manifold with the sensor in it.

I have a few used SL6 exhaust manifolds with the sensor hole.
Send me a PM if you need one.
DD

Sounds like one or both of the manifolds is pretty warped.

Napa sells new exhaust manifold for- are you sitting down?- $483.99.

Rockauto sels the SAME manifold (Dorman 674232) for $277.89.

Ebay has the SAME manifold for $264.95 with free shipping HERE

Amazon.com lists them for $233 plus shipping HERE

According to www.car-part.com, Merril's Auto Dismantling in San Bernadino ( 1-909-888-4768) has a manifold from a 87 Dodge van for $150

Alvin's Automotive Recycling, Inc. (1-888-833-9625) in Oakland has a manifold from a 1983 Dodge van for $150

Navarra Truck and Van Dismantlers (1-800-628-2772) in San-Jose supposedly has one from an 85 Dodge truck with broken bolts but doesn't list a price

Dorris Auto Wreckers, Inc. in Hayward (1-510-782-4393/1-510-782-4394) lists a "new aftermarket manifold" from an 82 Dodge truck but doesn't list a price.

So, you have some options. Don't give up yet. It all depends on how much you want to pay.

EDIT- Call Doc. I bet he will have the best price.

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Casually looking for a Clifford hyperpak intake for cheap.

You guys are awesome. I've done some thinking and this is my plan so far.

The Pick N Pull by my house has an 86 and two 87 pickups. I'll swing by there and see if any of them are a slant with the O2 sensor.

If that doesn't work, the guy at the machine shop I go to owes me an hour of labor. Maybe he'll be able to drill and weld in the socket for the sensor on the 64 manifold. Do you guys see any problem with this? I've never messed with cast iron so I don't know what works and what doesn't.

If that fails, I'll be contacting Doc for sure.

Reed, I saw that price on Rockauto and thought no way. Then I was looking up O2 sensors on Napa's site and about had a heart attack when I saw the price of their exhaust manifold "kit". Thats getting close to what I paid for the truck lol. I appreciate all the research man...you have been awesome.

Be sure to look carefully -- late-production slants without an O2 sensor often have a plug threaded into the O2 sensor port. One of those manifolds would work fine; just unscrew the plug and install the sensor.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan, good tip. I'll make sure to check for the plug if I don't immediately see the sensor.

Edit - Found out some more information. I talked to a friend of a friend who does smog and he said legally the O2 sensor cannot be moved more than 2 inches from it's original spot. He said putting it in the headpipe would be fine as long as it's a nice weld job and looks original. He told me that the techs don't have a book that they follow through every step. I guess they either know it or they don't and the only bit of information they'll have will be that the O2 sensor is supposed to be in the manifold. As long as the O2 placement looks original and isn't a hack job, most techs wont notice or even care because its not a performance enhancement like they do on Hondas and Acuras. He also said that exhaust leaks do not affect the smog results unless the exhaust leak is so large that they cannot get sufficient fumes out the tail pipe and/or if the exhaust leak is so close to the O2 sensor that it senses extra oxygen and causes the engine to run richer than it should.

All in all he said if I took it to his shop with the sensor in the head pipe, he wouldn't care as long as it passed the sniffer test. But he said I might as well do some work and find a manifold with the sensor already in it because you never know what will happen in the future.

His advice makes me believe that the "stealth HEI conversion" should work in CA unless you get the one off smog tech who is by the book and really knows his stuff inside and out. Either way, I'll worry about that at a later point because the Lean Burn is the least of my problems right now.