6.5 turbo diesel injector leak

[Sixfive]

I have a 1995 gmc K2500 6.5 turbo diesel and recently replaced IP, injectors and glow plugs. So far it’s been running good but a few injectors seem to leak fuel where the body of the injector meets the nozzle usually only when under high load.  Got the IP, injectors and glowplugs from pensacoladiesel.com. I’m not sure what to do about this as I am on a very tight budget. Should I try tightening the body to the nozzle? Runs and drives fine. There’s no smoke at idle or under load only the usual black smoke when stepping on the gas and black/white puffs on cold start that go away when the engine starts. I’m not sure if I should be worried of the injectors torching my motor as it idles fine and doesn’t smoke. I can post some pictures and a video tomorrow. Any advice would be helpful thanks. 

Also forgot to mention I tried cracking one of the injector lines loose to bleed the system and one of the injectors came unscrewed from the nozzle. All injectors are  tight into the block.