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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.
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 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 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.