If ur not using TURBO, to pump more air into ur intake manifold, there realy isnt that much pressure there, its whatever it sucks in. So i dont think its ever gonna leak unless its damaged. And if it does it will not be noticed, untill its pissing fuel everywhere. Worst thing is you can have a loss of power while driving because injector is not shooting right, if you dont wanna replace it now its fine.
If you wanna save money, u can trade your injector CORE for a used one at a junkyard and pay them a bit. Ive seen new ones go for 90$ each, and used ones appear for 15$ with no core. U might also just need to replace one or less. Depending on where the power is lost, im not sure how to diagnose that. because its before the pisons...
Before u assemble that stuff, check the CONDUCTIVITY or w/e its called. On each injector. It should read something like 14.0 or something, if its close there all fully functional. And make sure to put a dab of electric grease onto the connections to keep moisture out.
If you get any problems i would replace the set of em though, who knows. On ebay i got a FULL Gasket set that had those stuff for around 90$ free shipping? Or something. Now i have to remove engine agian and bla bla, so if you plan to fix car ur self u can never have TOO MANY GASKETS
and seals. The dealer one is better though or so people say... but its just very expensive.
Hope that helps.