Better Option... TBI or Carb for SBC 350?

[Tankota]

I'd recommend the EFI. That said I still have a quadrajet and won't get rid of it yet:whoops:
I REALLY like the sound of the HUGE secondaries kicking in at full throttle in the sand dunes. A standard 2barrel TBI won't do the same thing. Other than that and the fact I've only been 'wheelin' in the sand for about 3 years;p is why I still have a quadrajet.

Once you get in the typical leany spot with most carbs and the truck barely runs at all you'll be wishing you had the EFI...been there many many times.

I think....the 454 EFI might...might be a 4barrel. Is this guess correct?

 

[joeyg1973]

I wouldn't touch a painless harness with a 200 foot pole... but that is because I've used theirs in the past with bad results.

Unless you are going to run everything THEY say and where THEY say, you won't be too happy with the results.

As a counter point I have used Painless before without any issues at all. Never used their TBI FI harness, but I like their products in general.

 

[Trollhole]

Painless is painfull. Just way more stuff than you really need. You really need to think basic when going with TBI.

 

[cruiser enthuiser]

I am a one banana guy and I went with TBI because I didn't want to mess with a carb. I didn't want to rebuild it, or re-jet it and I was tired of my old one stalling and flooding just when things started to get dicey off-road. What if you live in the mountains but want to trip down to the coast? The beauty of TBI is that the ECM does all the adjustments for you and if set up right should provide years of worry free running. Forget about a choke, just turn the key and go.

I used the stock harness that came with my donor motor. Initially I was intimidated but with some good wiring diagrams I found that it was pretty straight forward and I appreciated the understanding I gained as a result. However, I was on a tight budget (when am I not??). I agree with the others that Affordable has attractive products as does Howell. A kit from these guys has the added benefit of some tech support.

ECM's are readily available at any junk yard and they are pretty tough. The 7747 is the most common, used on many of the 5.7L GM TBI motors of the late 80's. You'll probably need to tune the stock ECM by having a chip made (at least one) so factor that in to your budget.

There's a ton of info out in cyberspace on TBI conversions. Do your research and have fun with it.

-Ed

 

[nicholastheczar]

Ed -

Your write up you did on your TBI conversion is what started me down this road!!! I'm trying to do it on a low budget, but I don't know how long that will last. Did you have a good tech write up that you used during your swap? Do these chips cost $$$?

Nick

I am a one banana guy and I went with TBI because I didn't want to mess with a carb. I didn't want to rebuild it, or re-jet it and I was tired of my old one stalling and flooding just when things started to get dicey off-road. What if you live in the mountains but want to trip down to the coast? The beauty of TBI is that the ECM does all the adjustments for you and if set up right should provide years of worry free running. Forget about a choke, just turn the key and go.

I used the stock harness that came with my donor motor. Initially I was intimidated but with some good wiring diagrams I found that it was pretty straight forward and I appreciated the understanding I gained as a result. However, I was on a tight budget (when am I not??). I agree with the others that Affordable has attractive products as does Howell. A kit from these guys has the added benefit of some tech support.

ECM's are readily available at any junk yard and they are pretty tough. The 7747 is the most common, used on many of the 5.7L GM TBI motors of the late 80's. You'll probably need to tune the stock ECM by having a chip made (at least one) so factor that in to your budget.

There's a ton of info out in cyberspace on TBI conversions. Do your research and have fun with it.

-Ed

 

[jkl72-40]

option?

Go TBI and carry a carb....... If the TBI dies pop the carb in

 

[leftarmtan]

Another vote for tbi.I have a 350 with stock harness and a 4.3 with a painless harness with no problems.

 

[cruiser enthuiser]

Well, here's a few links of many that I saved. I found useful information in many places, but never found a comprehensive "one-stop" source of how-to do this conversion.

How to install GM TBI on any Chevy V8

GM TBI Swap

TBI Conversion

TBI 350 Installation - Land Cruiser Tech from IH8MUD.com

https://forum.ih8mud.com/hardcore-corner/106273-where-start-gm-tbi-conversion.html

Third Generation F-Body Message Boards


Yeah, a custom chip runs about $250 or better. Or you can learn to do it yourself. The 3rd gen website has some great info about that. This is one thing that I have not addressed yet on my conversion. It runs pretty good with the stock 7747 ECM but it would definetely benefit from a custom chip. I back-burnered it for now since I decided to do some painting.

Ed -

Your write up you did on your TBI conversion is what started me down this road!!! I'm trying to do it on a low budget, but I don't know how long that will last. Did you have a good tech write up that you used during your swap? Do these chips cost $$$?

Nick

 

[nicholastheczar]

Ed -

Thanks for the links. Those will help a bunch. I've decided I am going to go with the TBI route. I'm going to start gathering my parts and I'll try to document this setup for the next guy that is trying to do the same thing.

 

[nicholastheczar]

Do I have to use a wiring harness specific to my auto tranny? I have a 700R4 and I've found one on ebay (this one) that is for a 93 Chevy Suburban 2WD with a 4L60E tranny. Would this work?

 

[LandCruiserPhil]

Do I have to use a wiring harness specific to my auto tranny? I have a 700R4 and I've found one on ebay (this one) that is for a 93 Chevy Suburban 2WD with a 4L60E tranny. Would this work?

4L60E is controlled by the computer. With that said if the harness from the engine you use is set up for good. I would look for a 4L60 that does not need the computer and if also works better for clearance on the front drive line.