I have recently rebuilt/balanced S4 injectors with new o-rings and bushings on my s5 fuel rail/block (going to be run on s4 electronics) but it looks like there is a gap between bushing and the fuel rail. It has S5 grommet bushings and the injectors sit flush on the block

I don't want this to leak everywhere when i start it up.

 

The gap is bigger than it should be. Do you have the plastic spacer between the fuel rail and block?

 

it is hard to show from the picture but yes it is there. I'm thinking the upper o-ring is too big and its mushrooming.