I swapped out my stock single hole injectors for the orange colored Ford Racing injectors part # 0 280 156 013. I think they are made by Bosch. These injectors have 4 holes for better atomization and provide the same lbs of injection as the stock. They were easy to install, no adapters needed, plugged right in. I have noticed a little better throttle response and about 2 to 3 miles per gallon better gas mileage. I think (key word "think") they also helped lower my exhaust temp due to my headers not discoloring faster than others in the past, which of course eventually leads to cracking. When I swapped the new ones in, I also put in new up and down stream oxygen sensors and a stage 2 Jet chip (all in the same day) on top of the other past mods I have already done. Either way I am getting better atomization and in turn mileage. Bottom line these injectors are safe to use with no fuss.