Ok, there seems to be some misconceptions about fuel injection here. The bottom line is older TBI based systems are offer marginal performance gains if any, and are only marginally efficient against a well tuned carburetor. TBI is only capable of pooping fuel into the broad landscape of the intake just like any regular carb. It is true that with the precision of injectors, the amount of fuel given can rapidly fluctuate (why EFI systems can have better throttle response). Also, with high pressure EFI, fuel can atomize more efficiently. Lastly, air to fuel ratio adjustments on the fly are hard to beat. BUT, let us not forget the nature of these stock TBI systems of this era was for “efficiency” in MPG, not performance, and as noted earlier, the economic gains were marginal.
Where the real-deal EFI comes in is with any MFI (Multi-port Fuel Injection), DPI (Direct Port Injection), CPI (Central Port Injection), or TPI (Tuned Port Injection). The common thing between these systems is “port injection” – meaning all of these systems employ an injector per cylinder ratio. With the understanding that in most cases, many small machines/engines/forces working together are frequently more efficient than one large one, a broad TBI system can be compared to an MFI system.
For reference, three 2bbl carbs were the hot setup back in the day for a few reasons; they administered fuel very well, were efficient at all operating levels for the most part, and had GREAT throttle response since the venturis were small (opposed to fewer large ones). Now, if it weren’t a nightmare to set a small 1bbl carb for each cylinder up, we’d be set (ever see OLD FI systems or multi-carb Hilborn setups?).
The point is you won’t gain much unless you get serious about setting an injector per cylinder rig up. Long story short, I’d get some fuel injector bungs or machine an intake to accept injectors, accept the challenge of setting fuel rails up, and use a universal air-only throttle body with a 4bbl pattern, and hook it all up with an 80’s TPI (or later model LT1) harness with a wildly burned prom accounting for modifications and engine size.
The beauty of a TPI harness is it’s that it’s extremely simple (primitive), yet amazingly efficient. Since the ECM is also “primitive” by today’s standards, it is very easy to “hack” for modifications. On a simple level, I think about any “4bbl” bolt pattern TBI body could be plopped onto any 4bbl carb manifold (or even “2bbl” base TBI setups with a 2-to-4 adapter). I know there are some differences in the manifold bases, but it’d not be hard to change.
Just my input on EFI; I’d say “long live the carb”, but EFI is GREAT when done right :bonkers: