TBI to LS?

[thirdstreettito]

What all is involve with swapping from a TBI 350 to a 5.3 LS? Excluding motor mounts and trans adapter(s). I can get a 5.3 shipped for $400 with less than 120K miles on it, which is cheaper than upgrading the TBI 350 to try and achieve LS engine MPG. Thanks, Bradley

[CamaroChris]

http://67-72chevytrucks.com/vboard/s...d.php?t=456787

[thirdstreettito]

Where's the TBI swap info in there?

[CamaroChris]

Read through it, Read build threads, try the search button. There is so much info in this forum. you just have to spend some time researching.

[CamaroChris]

The only thing that I would think you would even keep from the tbi set up would be the fuel pump. the Ls motors pretty much hold their own. stand alone 4-10 wire hook up. read through glocks build

[thirdstreettito]

I have searched. I found a bunch, but I dont know how to sift through all the technical stuff to get to the lamens terms of stuff. Like, how do I deal with the ECU? How do I hook up the ignition? What CAN I use from the TBI, what CANT I use from the TBI? Etc Etc

[BR3W CITY]

For the ECU;
You need to have VATS, EGR, and rear 02 sensors tuned out, this will allow the engine to function normally without all that stuff (which 98% of us have removed). At that point, any additional equipment like cam or injectors can be compensated for so the vehicles can start and maintain a decent idle. You also calibrate for rear tire size and rear end ratio in the tune. This is usually done through something like HP tuners. Mail order tunes can do this for you, but NOTHING replaces a true tuning session with a pro.

Ignition: if you have a harness made for you, ignition will be just a couple of wires to hook up to your ignition switch and a power source. Very easy.

You'll need a new fuel pump that can supply to correct pressure, and with that you will need to replace any low pressure fuel line with Fuel Injection safe rubber or braided line. You will either need a vette style filter-reg, or a return system depending on which motor you are using.

You really won't be keeping much of the tbi. The wiring for the ls engine is mostly self contained in the harness, and there is a minimal # (IIR less than 10-12) to hook pretty much everything up. None of the SBC components will be kept, nor will most of the fuel system. You will want to keep the sbc mounts to bolt your adapter plates to for the ls style engines.

Not really sure what you'd want to keep off the TBI anyway.

[Gordonr1973]

Originally Posted by thirdstreettito

I have searched. I found a bunch, but I dont know how to sift through all the technical stuff to get to the lamens terms of stuff. Like, how do I deal with the ECU? How do I hook up the ignition? What CAN I use from the TBI, what CANT I use from the TBI? Etc Etc

You have to read Glock's thread from start to finish. It pretty much tells you everything you will need and where to buy it if you can't locally. His was a 5.3 as well.