How many times have you sat on a trail and waited for a guy with a carbureted engine in front of you to climb that steep or rough section up ahead, only to watch him stall out over and over because his carb keeps flooding out? You know the drill. The guy has to go through the ritual roll back, restart the engine, rev the snot out of it to clear the flood, and then put it in gear to try the obstacle another time. He lines up, gets on the throttle…and stalls again. While you’re sitting there sniffing the unburned fuel spewing out of the truck, you are thinking how electronic fuel injection (EFI) was made for us off-roaders.
Sure, people will tell you that fuel injection was invented for cars, and for getting better fuel economy or cleaning up emissions. But the truth is that EFI never shines brighter than it does in our off-road rigs. And that’s because we ask our engines to function flawlessly in situations other engines would never see. We go vertical, bounce all around, idle for hours in desert heat, and lug the engine rpm down way too low. EFI is great at doing all these things, and when GM introduced the throttle body injection system (TBI) on its V-8s in 1987, we were immediately spoiled by how forgiving it was even when we abused it. That is until we tried to modify it for more power.
To keep the carb guys from having all the fun we dug up a few engine modifications you can make to keep up with all your four-barrel buddies. Just keep in mind that you can’t get too radical with these engines because supplying them with enough fuel and keeping them emissions-legal are huge limitations. Figure 360 hp as the most you’re going to get out of a TBI 350. If you want any more than that you’ll have to move up to a multiport fuel injection system…which is always an option!