Just bringing some personal insight to this, great discussion BTW. I have a '93 K1500 with factory TBI, it has had a few issues over the years but all in all it very relaible. This truck was designed to support fuel injection, in-tank fuel pump, fuel return lines, O2 sensors and the like. The engine in my '93 is stock. I have built several 4.3L V6's for people with great results. I built one for an S10 blazer that pushed over 400Hp on a Dyno, it tore the center out of the flex plate once it was installed in the truck. The point is to install a TBI on a non TBI vehicle all of these additional systems must be considered in the build.
I say this because having installed a Snipper EFI on a '57 3100 with an early '70's 350 V8 it became a mess very quickly. The Holley system directs all of the fuel and electrical connections out the rear of the throttle body, the area is already filled with the distributor, coil and various lines. Add to this that the fire wall is fairly close as well. The fuel lines run over the back of the engine block and down to the frame rails and are routed to the tank. The addition of a return line adds some issues it self, if the tank is in the factory location that is must be considered, if the tank is mounted to the frame (as many are) it still must accommodate the addition of a return line. The Holley system supplies all of the materials to install this EFI, the clamp on O2 bung and rubber fuel lines just made it feel cobbled together. All this can be done but it should be planned well ahead.
The discussion of the 4.3L TBI is much the same, it can be made to work, it just needs to be planned out. By "It can be made to work" that doesn't mean it will work well. As mention earlier there are some big differences in the make up of a V6 versus an L6.
I think that a Hybrid approach could be done, Jerry said the use of single port injectors with separate crank sensors could be done. Adding the fuel management ECU and being able to tune it correctly would be the hard part. Cost wise would it be worth it ? No , but it would be COOL.
Last edited by TUTS 59; 06/09/2023 1:08 PM.
