Fitting the kit has been the hardest part of the engine build

Right so i got the kit on.......the end which sprays only came with a plastic washer a seal and a cap.....now i have it as plastic washer (which is loose on injector but is the perfect size for the inlet manifold) a seal and then the cap....does that sound right????????

Now i have heard run without a cap......no can do or the plastic washer/o-ring would just fall off..the cap actually holds it together in the inlet.So how big to i drill the cap out to????As big as poss??Is that gonna be enuff to give a good spray pattern???

Many thanks.