Vortec Engine to TBI Swap

[Chewy1576]

I'm going to have the entire TBI system out of my 1990 K2500 here shortly, switching over to a Fitech system. PM me if you're interested in any parts.

 

[Gramps]

The stock tbi system is very reliable, but it can be challenging to tune. Prom chips need to be burned - can’t just plug it in and change settings. But if you choose your parts carefully it can be built pretty stout on the stock chip.
The one I had dynoed in the spring pulled 300hp 385ft-lbs on the stock prom chip.

 

[ccreddell]

I agree that youre over thinking this a bit. I swapped over to Vortec heads (which is the main difference between a TBI and Vortec engine) and just slapped a Edelbrock 4V manifold on with an adapter. If you look at my sig youll see I did a few other things too, but basically the part I mentioned is all you need to do. Ah...I take that back. Youll need to swap in a TBI distributor too. As far as someone above saying you should use the vortec FI I would say theyre high. The Vortec motor was a great motor but the fuel injection was on par with the LT1s Optispark-nothing but trouble and no way to really modify it. Not to mention too anemic for any real modification. And unless you trade up to the 0411 ECM, its not really tunable. And I know the marine intake guys will have a fit about those statements, but even with the marine intake the cost (and work) to benefit ratio is pretty bad. The Fitech (and other similar systems) are a great way to avoid all the tuning and such, and the prices are coming down, but the TBI (with the computer mod I did) is easily tuned and is good to 350-400hp easily. Im running about 300, and have gotten up to 25mpg with the lean cruise actuated. Im prepping a 383 ATM to put in it and if I need to get more air into it, a 454 TBI base will get me all the air I need. Its a simple system that is bullet proof and will last you forever.

 

[ccreddell]

The stock tbi system is very reliable, but it can be challenging to tune. Prom chips need to be burned - can’t just plug it in and change settings. But if you choose your parts carefully it can be built pretty stout on the stock chip.
The one I had dynoed in the spring pulled 300hp 385ft-lbs on the stock prom chip.

Actually, you dont have to burn chips for these any more. A simple daughter board soldered to the ECM makes it plug and play (or tune) and its really pretty simple. Look up EBL flash-works really well.

 

[Chewy1576]

I agree that youre over thinking this a bit. I swapped over to Vortec heads (which is the main difference between a TBI and Vortec engine) and just slapped a Edelbrock 4V manifold on with an adapter. If you look at my sig youll see I did a few other things too, but basically the part I mentioned is all you need to do. Ah...I take that back. Youll need to swap in a TBI distributor too. As far as someone above saying you should use the vortec FI I would say theyre high. The Vortec motor was a great motor but the fuel injection was on par with the LT1s Optispark-nothing but trouble and no way to really modify it. Not to mention too anemic for any real modification. And unless you trade up to the 0411 ECM, its not really tunable. And I know the marine intake guys will have a fit about those statements, but even with the marine intake the cost (and work) to benefit ratio is pretty bad. The Fitech (and other similar systems) are a great way to avoid all the tuning and such, and the prices are coming down, but the TBI (with the computer mod I did) is easily tuned and is good to 350-400hp easily. Im running about 300, and have gotten up to 25mpg with the lean cruise actuated. Im prepping a 383 ATM to put in it and if I need to get more air into it, a 454 TBI base will get me all the air I need. Its a simple system that is bullet proof and will last you forever.

I have a TBI intake bored out to 2” and a big block TB on the shelf I was going to use for a 383 until I decided to go with a Fitech system. PM me if you are interested in anything.


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[Bret]

I agree that youre over thinking this a bit. I swapped over to Vortec heads (which is the main difference between a TBI and Vortec engine) and just slapped a Edelbrock 4V manifold on with an adapter. If you look at my sig youll see I did a few other things too, but basically the part I mentioned is all you need to do. Ah...I take that back. Youll need to swap in a TBI distributor too. As far as someone above saying you should use the vortec FI I would say theyre high. The Vortec motor was a great motor but the fuel injection was on par with the LT1s Optispark-nothing but trouble and no way to really modify it. Not to mention too anemic for any real modification. And unless you trade up to the 0411 ECM, its not really tunable. And I know the marine intake guys will have a fit about those statements, but even with the marine intake the cost (and work) to benefit ratio is pretty bad. The Fitech (and other similar systems) are a great way to avoid all the tuning and such, and the prices are coming down, but the TBI (with the computer mod I did) is easily tuned and is good to 350-400hp easily. Im running about 300, and have gotten up to 25mpg with the lean cruise actuated. Im prepping a 383 ATM to put in it and if I need to get more air into it, a 454 TBI base will get me all the air I need. Its a simple system that is bullet proof and will last you forever.

A lot of what you describe is exactly what I had in mind. For a vehicle subject to emissions and safety inspections, the vortec injection system/Marine intake modification may be worth it, but for the 1967 Chevy this engine is going into, none of that is worth it imo. I had assumed it would be a lot cheaper to get on the fly tuning for the old TBI system, but the unit you mentioned is still $400, with no option for self installation. That's starting to get up there with the cost of Holley and FITech units. With what everyone here is saying, seems like my best bet will be to stick with my carb and maybe add on a Lambda gauge for fine tuning.

 

[ccreddell]

I personally would never go back to a carb-for all the reasons you put forth in your first post. Besides, a decent carb is up around $600 or more anyway. You can get a TBI and harness and computer for next to nothing....The gas savings alone are worth it to go EFI, and the rest of the advantages just seal the deal for me....

 

[Bret]

I already have an Edelbrock 650 that is on the current engine, I originally got it for $200 plus the cost of a rebuild kit. For TBI parts, the Pick a part near me is always running 40% off sales too, and absolutely no lack of GMT400s. They even had a 92 3500 with 454 and throttlebody still intact when I went yesterday. The car is by no means a DD, so fuel savings don't matter a ton for me.

 

[L31MaxExpress]

I already have an Edelbrock 650 that is on the current engine, I originally got it for $200 plus the cost of a rebuild kit. For TBI parts, the Pick a part near me is always running 40% off sales too, and absolutely no lack of GMT400s. They even had a 92 3500 with 454 and throttlebody still intact when I went yesterday. The car is by no means a DD, so fuel savings don't matter a ton for me.

Just a tip for TBI swaps. If you go the junkyard route, the fullsize van harneses are easier to mess with and the wires to the ECM are much longer than the truck harnesses allowing you more freedom on ECM location.

 

[CrustyJunker]

Just a tip for TBI swaps. If you go the junkyard route, the fullsize van harneses are easier to mess with and the wires to the ECM are much longer than the truck harnesses allowing you more freedom on ECM location.

Cool piece of advice. I heard a rumor that a neighbor of mine has an old mid 70's Cadillac that fails emissions. My fantasy was to buy it and adapt a TBI on it in some fashion. Since it has to be emissions compliant, it won't be fast, but thought it would be a fun boat!