I have an 85. It's stock except for RRs and duels running to hooker headers. Has anybody converted a TPI to a carb? I see these Edelbrock power packs claiming to make good numbers on stock 5.7s. What all has to be changed to do this? I'm worried it will mess up my computer, my digital gauges may not work, stuff like that. Any wisdom you could provide would be a huge help. My valvetrain is about to bite the bullet. If I have to pull it out anyway I might as well get more ponies but I'm looking to do it on the cheat. Any ideas?

 

If no one is going to answer I will. It will work and you will get more HP cheaper. I would use a different distributer and coil. You will lose your MPG display, but you won't want to see it anyway. You will have a permanet check engine light and will never pass a smog check. May not be a big deal now but you never know.

 

Converting to carb... kiss your ECM good bye (although it does eliminate that stupidly expensive MAF module that's unique to '85)

 

There are several of us here that have made the conversion. Please do a search and complete that research first. I'm pretty sure you will access some very good info within the forum search component.

In general, the conversion was not that difficult overall. The carbed engine, if set-up correctly, will provide both advantages and dis-advantages over the TPI system. While it is your car and you should do what you want to make yourself happy, the decision should be well thought out.

For me, my 85 was not well-maintained and it continued to give me one problem after another....computer and "code" related. The problems left me sitting along the road several times. All of this coupled with my knowledge of carbs and my unwillingness (admittedly) to spend the time and effort to learn TPI technology, led to my conversion.

Finally, be warned....you will likely see several posts from carb haters. In the past, those negative posts provided no value to the thread.

PM me if you would like additional specific info.

 

Heres the way I see it...

TPI = driveability (gas mileage, easy starts, etc.)

Carb = reliability (no stupid sensors to mess with, will ALWAYS start)

Its cheaper to go with the carb and you'll probably get more power, but you will suffer at least 5 mpg loss and the fact that your '85 is not even close to being original. Its a pain disconnecting everything, did I mention that?

 

I am one of the so called, "carb haters". Let me set the record straight, I am not a carb hater. I have worked on, and know carbs, better than I know EFI. What I dislike and think is a sacrilege, is moving backward in technology, retrofitteng the most technically advanced car of it's day. Nostalgia is great too. But I am one who just happens to think that a flathead, as great and nostalgic as they are, doesn't belong in a C4. The TPI is restrictive. Properly done, a carb can take care of that. So can a better flowing EFI set up.

I agree with Jansenwins. Consider all the angles and ramification, and in the end, it is your car, even you turn it into a meld of new and old.

RACE ON!!!

 

Very good perspective from one of the most knowledgeable members of this forum.

 

the TPI is a great torque builder, a great gas mileage enhancer, you can't flood out the TPI unless there's a leaking injector.
The carb is a great low tech horsepower enhancer compared to the TPI, but the torque falls off, and gives you less mileage, and the EPA police won't let you relicense your car without going through the arbitration hoops, and even then they may revoke your ability to get your car licensed for the street forever.
I have a truck with a carb, and the biggest pain with it is if I don't drive it 2 or 3 times a week, the gas evaporates out of the carb, and I have to grind and grind on the starter to refill the float bowl, then the possibility that I might flood the cylinders in the process, and then it seeps gas a little until the gas swells the gaskets, and seals everything back up.
Then the other problem is the automatic choke. The average temp here in the summer daytime is 115, the choke never goes on, so there's a driveability issue until the engine is up to about 170, because the carb manifold is a wet manifold, and without the extra heat helping to vaporize the fuel in the airflow path, it doesn't drive that great till the temp comes up. never happens with TPI.
When the engine is hot enough, the carb drives great. no problems.
I enjoy having a carb, because I am proficient with "old technology". I can drive any carb fueled car because I own one.
I can un-flood a carbed car, start one that hasn't been driven in a long time, and be able to troubleshoot driveability issues and make adjustments where others that never had a carb are lost.
The sad problem today is time. Everybody is becoming impatient. when people run up against something they don't understand, they REPLACE IT. whether that is carb for efi, or a dishwasher vs a trash compactor. The answer is to educate yourself, and find out what you don't know.
If you bought a car with EFI, fix it. If it isn't fast enough, modify it.
changing out a fuel management system for another doesn't solve all the problems associated with why you changed the fuel system in the first place.
Everything is a compromise. To have EFI, you must acquire knowledge to repair it, and discover it's compromises. To have a carbed car, the same applies.
the difference between EFI and carbs, besides cost, is the person that doesn't take the time to learn a complicated system, falls back on low tech because it might be simpler to discover the problem with the low tech system.
Yes the carb might start every time, but if you can't get it past 25 mph, and the EFI might not start, isn't the result the same? no driveability?
Granted, if you were in timbuktu, and the EFI wouldn't start, the carb will get you 50 miles or more to a place where you could get it fixed......but If you had the knowledge to fix your own EFI system, who needs to drive it anywhere?
Suddenly you have become self sufficient, you are able to repair your car, or someone else's car without even looking at it based upon your experience and knowledge.
Even if you hate working on cars, with experience and knowledge, no one can take advantage of you if you take your car in to get it fixed somewhere.
They say knowledge is power. but knowledge by it self is worthless.
Success is a three legged stool. one leg is knowledge, one leg is experience, one leg is common sense. with these three things, you can be a success. with this combination, either the carb goes on, or the EFI stays put, you will be the winner.
just my 2c
Now will somebody please smash up this soap box now that I have gotten off of it?

 

Keep the EFI, infintely tuneable at any RPM, moreso than a carb (and I happen to be a fan of carbed app's, too).

Some modern heads, a mild cam and a good intake will stomp all over the power numbers any of Edelbrocks packages make and have perfect driveability. Save a little more and get the best of both worlds.