How tight in the fuel rail should an injector fit? The reason I ask I am using a set of custom rails that take a odd ball oring and the fit is "snug" but not tight like factory rails. I have never used anything but oem rails so is this normal or should I ditch these for a set that takes regular orings?

If you used Vaseline or another light grease they
slide in sorta easy... but they almost pop in

I used alittle vaseline on each one and they slid in real easy it just kinda made me wonder whether to try them or not

+1, when lubed, it should be fairly easy...

Just for the sake of locating parts easily, I'd prefer using the factory o-rings...but custom parts are cool...haha

Tried them out, they hold up to 50psi For some reason these rails were machined to take a 16.5mm o ring. I really don't understand why but the only orings that worked were from a 1983 Porsche 911 sc lol