Do you know the history of the used 383? If it were me I would just go with the 383 and 200 4/R. The engine would drop right in, and transmission will fit the existing cross member and will not require the drive shaft be shortened. The time saved with this will get you back to enjoying your car instead of the headache of dealing the conversion required to get the trunk engine an transmission to work. The only downside I can see is you are not going to have the benefits of fuel injection. Maybe that really isn't a downside.

 

The truck motor swap and 4L60e swap seems like a pretty good option.

As others have mentioned you can use the stock fuel tank and a Walbro in-tank high pressure EFI pump with the 82 sending unit and a Holley "Hydramat" to prevent fuel starvation in hard corners with low fuel levels. (I did this +new Earls Vaporguard fuel lines in my 79).

It bumps up the cost of the swap, but Holley now sells the "Terminator X Max" EFI system for EXACTLY this purpose (LS Swaps into older cars; it JUST came out within the past month) and for $1,299 you can get a brand new holley self-tuning EFI with a new harness and the ability to control both the engine and transmission fully: https://www.holley.com/products/fuel...or_x_max_kits/


I think the truck LS and 4L60e swap is just PERFECT for your 3.08 rear gears, too. The first gear will help you accelerate from a stop light better than a TH350 and your 3.08 rear gears plus the 4L60's OD gear,the baby cam in that truck motor, the long-runner truck intake, and the ability to tune a lean highway cruise AFR with the Holley EFI should get just FANTASTIC fuel economy. Wild-*** guess you should clear 20 MPG highway cruise easy with that combo and long-tube headers.


Adam

 

Not as simple and cost efficient as just going with the 383 and 200 4r which would almost be plug and play.

 

You can technically flip the stock trans cross-member upside down and make a 2WD 1 piece case 4L60e work; not sure about the 2 PC, 4 wheel drive version of the 4L60e...
Bowtie overdrives also makes a REALLY NICE cross-member for 700r4s / 4L60Es -it's arched so that the exhaust can pass UNDER it instead of OVER it and it's quite a bit lighter than the stock piece and adds much needed frame rigidity to our old C3s. (I went with one of those for my 4L60e swap.)

-Then just take your current drive shaft to a drive shaft shop and get it cut, welded & balanced and slide and bolt it back in: Bob's your uncle!

Adam

 

Maybe your way is the best. Pics?

84-91 C4 has reverse rotation short pump with serpentine system. That works, ... electric fan ...or modify a pump drivehub & clutch hub to mate.

Of course you cannot use a standard fan with reverse rotation pump or vice versa.

The bypass can be easily solved by several easy methods.

 

The main information that I have regarding the used 383 is that the current owner used it in a toy type car and was removed and placed for sale to fund a bigger and better engine. I came across it as an ad that happened to be posted by the engine builder that was recommend to me.

While I like the luxury of the fuel injection in my truck, I believe that a properly setup carburetor is adequate for daily driving. Please correct me if I am wrong, but the main area that I can see a potential issue with drivability is if I am driving through the mountains and going through significant altitude changes.


Kael

 

The altitude change can affect performance quite a bit with a carbureted car, but it won't by itself make the car run poorly. I had a 76 Ford Elite way back when, a 351 W carbureted car. It ran supernice got goood gas mileage for that size and year a car and had adequate performance for normal driving but certainly a disappointment from an acceleration point of view. I drove this car from Regina Saskatchewan to higher elevation in Calgary and there was a surprisingly large drop off in horsepower for an already slow car. It still ran and drove fine, so that's the issue I see you having with a carbureted car tuned for lower altitudes being driven in higher altitudes.

 

Today I had a valuable reminder as to why I originally did not request a diagnosis to the sluggishness of my car from the forum. From my brief experience on this (and other forums), I believe that everyone who provides information truly intends to help. Please be aware that I do not mean to be disrespectful to anyone with this post. If it comes across that way, I apologize. I will be the first to admit that I have asked for help from an online community including in this very post. I have learned that an online "diagnosis" can be valuable when used as a guide as to where to look for the answers and to be made aware of simple things that may have been missed, but it will never be the same as an in person evaluation. An online diagnosis is not sufficient to determine the actual repair that is needed.

Today, I was working on my son's truck because it has been occupying the space where I will be working on my Vette in the near future. He has previously complained to me about it not running correctly, but because I am a shade-tree mechanic instead of an officially trained mechanic (expert), he was hesitant to ask me to look at the truck. He explained in at least one online repair platform that the truck was struggling to start and idle, cranking but not firing, dying when placed into gear, surging while driving, using excess fuel, creating black smoke from the exhaust, not accelerating, etc. Because these "experts" suggested fuel related issues, he has thrown many parts at the truck without any change in operation. He replaced the fuel filter, then the fuel injectors, then the fuel pump and tank. The pump was later tested and found to be in good working condition. As he was removing the tank, he wrecked the fuel lines so he also got to replace the lines from the tank to the tbi unit. Since he didn't get a result after these changes, the fuel pump relay was replaced. Then came the suggestions to replace various sensors which haven't been replaced yet.

After no changes even after all of these parts, I suggested that it would be money well spent to take the truck to a local service center for official diagnosis. He made an appointment for tomorrow and could not get the truck to start so he was going to get it towed to the shop. I suggested that I take a look at it instead of towing it. Since the appointment is for tomorrow, I figured that he could always get it towed tomorrow if necessary.

I checked the basics of air, fuel, and spark. When checking spark, I found that it very weak and was sporadic. When I checked the coil wire and distributor cap, I found the following issues. I'm no expert, but this sure doesn't seem like a fuel related issue as he had been led to believe.








Surprisingly, when the center terminal broke off, the metal contact was still inside of the wire. That metal contact was still able to occasionally make contact with the rotor which allowed the truck to still run.

Needless to say, he is a little embarrassed to say how much he spent on the parts before agreeing to pay for an official diagnosis. I am thankful that this became a teaching moment for both of us.

Kael

 

why not get a $50 cam shaft and put it into your c3. If you go after an engine swap and or trans upgrade it could become a never ending project.
If the engine is already toast because of metal debris in the oil it would only be a few bucks and 1-2 days lost.

 

I tend to agree and have a similar perspective although obtained via different experience, I'm sure.

Fairly early in my career, I started working in Microsoft's Customer Support organization, answering technical calls from systems administrators/engineers and trying to remotely troubleshoot issues over the phone (no fancy tools that would let you remotely see what was on their screen back then in the early 2000s). They taught a very structured troubleshooting methodology that was adopted from the medical community and doctors to diagnose problems starting from very SUBJECTIVE observations and statements only.

The keys of the process are: foundational understanding of how the technology at hand works, and then applying a logic tree that enables you to go from subjective experiences of how the problem manifests (symptoms) through that logic tree in the least number of steps possible to determine the root cause and the one fix that resolves all symptoms / problems. You start with the SUBJECTIVE experiences / symptoms and then ask clarifying questions to narrow down the universe of possibilities and then you move on to gathering OBJECTIVE data that can actually be used to ANALYZE / EVALUATE the problem objectively with the ultimate goal of identifying the ROOT CAUSE and then offering up multiple solutions to that root cause that the end customer can be happy with.

The process is called "SOAP" and is used by the medical profession to drive outcomes that solve the root problem and aren't a "shotgun" approach at troubleshooting or treatment guess work; it's also used for case documentation to fight off lawsuits in the medical industry, I'm told.

Subjective: "What are the SYMPTOMS?" What problem are you EXPERIENCING? -Sound, behaviors, feelings.-When does it occur/ not occur? How bad? Do you have strong exhaust fumes? What do they smell like?

Objective: Please open up this log / file on your computer and tell me what error messages are there. Is there any discoloration on the spark plugs? -Can you send me a clear and close picture? What temp does the thermostat read when this happens? What does the multimeter say in Ohms when you test across all spark plugs? etc...

Analysis: Keep going down the logic tree ruling out possibilities and gathering more OBJECTIVE information that you can use in your ANALYSIS to get to a ROOT CAUSE.

Plan: "Prescription" A proposed list of options for addressing the root cause (recondition part, new park, procedure to go through; surgery to undertake, medicine to prescribe, configuration change to make, etc...)
Validate that plan addressees root cause, relieves symptoms, and doesn't cause new symptoms / problems.



Troubleshooting all the way to root cause is HARD and time consuming and the logic tree that makes it possible / efficient requires understanding the breadth AND width of the domain in which the problem occurs.

Big industrial facilities and commercial breweries utilize something called "Fishbone diagrams" -one per behavior / problem that walk you through what could cause a problem. IMHO, questions posted on an internet forum towards diagnosing a complex problem in a complex system are largely useful for populating your "fishbone diagram" / understanding of the OPTIONS for what it COULD BE/ to understand how to make your logical tree and to begin testing options by gathering OBJECTIVE data to do your analysis to get to root cause. (If you hate "shot gun" approaches to problems / hate throwing parts at problems.)


Adam

 

I troubleshoot machine for a living and am self taught.
There is no way to explain my process of troubleshooting other than deductive reasoning or Ochams razor.....each situation is different but I am usually successful....
I can tell you this much though....it comes to me very fluently what to do to narrow down a situation....most times I have to work alone because people get very frustrated watching me because what I am doing is not what they are doing.....well if what they want me to do is so damn good then why am I here? I usually have to explain my way of doing things in a manner that once read and absorbed make the person realize that doing it any other way is rediculous.
I approach engine questions here on the forum in the same manner.....there is a chain of deduction that happens but once you get to a point....there is really only one way stuff should happen....
This is why I keep my mouth shut anymore and nod at car shows and at the track....there is a giant faction of people in this world that want to do **** wrong and tell you it is right as not to deface themselves.....
If you can get past this.....then you may be able to teach yourself how to troubleshoot.....it is an organic thing and cannot be taught to a person....
To effectively troubleshoot though the most powerful tool you can have is to know how things....all kinds of things....work.....then you can go at a situation and narrow it down.....it is a level of confidence that is trial by fire and not exactly earned as much as it is burned in to your brain......
And all of that “Toyota Effect” (fishbone diagrams, lean, 6 sigma) are all crap to me....they have no value to someone who really knows how to approach something....that stuff is for folks who want to pretend they have a clue, and in a room of ten....two might actually have a clue....the other eight rely religiously on the fishbone and other tools.....

Jebby

 

I believe that happens because things get assumed like we assumed he checked under the hood for things wrong, or as mentioned above tech support calls about computers not working. We forget not everyone is as knowledgeable and don't know to complete the first steps of the trouble shooting process before saying it was running great and now it wont start.

 

Now that the truck is out of my workspace, I will be bringing the Vette into that area, I will go back and confirm whether or not the valves are actually moving. Once I see for myself what is happening I will determine my next steps

Kael