TBI or carbs?

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Jables

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So, got a 92 5.7 TBI... Got a lead on a kit to swap it to normal carbureted. Opinions?

And should I keep it TBI, is there anything I can do to get better performance outside of what's in the sticky thread?
 

Darrell

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Why and what exactly are your plans? Are you planning to make more power than the TBI can handle? Changing your trans among other things as well ? Lots of unknowns !!
 

Jables

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Well... For starters, I don't know much about the TBI system, and what it's capable of... I'm more familiar with carbs. I just want some more torque, and get as much as I can out of stock internals for now. This will also be my DD, but I'm not concerned about mpg... Used to own a Mazda rotary. I'm having issues right now with low idle, and a weird "hiccup" when holding steady on the gas at higheah speed. Like it loses power for a second and goes back to normal. Also dies if I turn the wheel at a standstill. I'm not sure if this is related to air/fuel delivery or not though.

But anyways, all that might not be related. I'm just unsure of what's more reliable, or has more potential, or basically what the pros and cons are of each style...

I'm basically retarded with TBI...
 
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Darrell

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When you stated "a lead on a kit" ... what exactly is in this kit and how many miles is currently on the existing engine now? I'm not an expert by far on this and maybe someone who is will chime in and help. But I just about crossed the same bridge as your wanting to until I was talked out of it by an old engine builder and I'm glad I listened.

The TBI system is not that bad actually. If your going to run pretty much stock just stay with the TBI and change a few things. It'll be much cheaper and get you what you want without the headache of a carb swap.

The TBI is an electronic system. If you convert to carb, then you'll need another intake, distributor, trans (non-electronic) such as a TH700, throttle kick-down cable just for starters. In all it can become a ball buster.

I don't know what your budget is so you could just start with a rebuild kit for the TBI and new injectors (shave off the air dams ... optional) and see where that gets you. Rebuilds are pretty straight forward actually.

I just rebuilt my '95 5.7 TBI from top to bottom and kept things pretty stock as I wanted some pop yet DD friendly too. I'm not saying you must do but it'll give you some sort of direction.
- Stock rebuilt heads
- Edelbrock performer-plus cam and lifter kit #3702 (torque from the low-end to the mid-range and is a smooth idling cam for daily drivers)
- Edelbrock performer TBI intake #3704
- TBI distributor and ignition coil and all the other upper misc parts, i.e. spark plugs, wires ect.

hope this helps
 

Jables

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It does a bit. The "lead on a kit" I mentioned is a friend of mine has a similar truck, another 92 with a 350 in it. He bought a kit that included a new intake, a 4 barrel carb, dummy sensors, etc. Decided to go a different route and just rebuild the truck to stock. So he's looking to get rid of the kit. Offered it to me for $400.

If it's gonna be more hassle and may need a tranny swap, then I'll probably just forget it for now and mod out what I have until I can save up more cash. I'm still uncertain when it comes to the tranny in these trucks, I know eventually I'll want to upgrade, think I have a 4L60 in it now, but really not sure. I know the truck had some aftermarket "tow package" upgrades, but not entirely sure what that means. I know the rear differential and suspension were modified but don't know how.

That's a different discussion though. IllI stick with simple upgrades to the TBI system for now. I already have new ignition components ready to go in Sunday (plugs, wires, etc), I'll try the air dam shave and maybe look at a new intake manifold soon. Any other suggestions, or is changing injector sizes and such kinda out of the question/unsupported?
 

884x4310ci

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Being a 92 you could still have a th700r4 and not a 4l60e. So find out what Trans you have.
then you need intake carb and HEI and a gasket kit. Very simple. Mine runs a lot better now I did the swap.
starts easyer too.
 

89GMCJOHN

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I just got done going from TBI to carb...there are issues that must be addressed ..in a nutshell ..

Fuel pressure must be knocked down to 5-7 psi for your carb ....whether you run the factory electric in tank with an external regulator or run a straight old mechanical style pump its your choice ....I personally ran the old mechanical pump as I didnt want to deal with the ECU , its oil pressure switch, all the relays etc ....then you have to address the pickup in the fuel tank..if you go mechanical make sure your block is drilled for the old mechanical pump and your camshaft has a fuel pump lobe - some dont .

Distributor you need to go to an old school mechanical HEI - no biggie .

Hopefully your tranny is not electronically controlled if you go carb or you will have to address that . My 700r isnt - so that was easy .

Its not a cheap swap but I like the whole old school setup in a newer truck idea and I like that I can upgrade in the future without computer tuning, tuners, chips etc ,,,,,

As others stated above tbi is going to be cheaper, you can add a cam , but then you have to deal with the tuning.
 

Jables

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There's a lot I still have to learn, I don't even know how to tell what trans I have. According to a sticky I was reading, I should have the old non-electronic style 4L60, based on the trucks year, but I really don't know. It may have been swapped out when the "conversion package" was put in, whatever that really means...
 
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