I just bought some used 450cc injectors for my upgrade from an auto setup to manual. Im missing one of those little black caps at the end of the injectors...and another is damaged. Is there anywhere i can buy a couple of those?

Also, Im going to be swapping in a manual ECU with my new injectors, so i have the correct fuel maps. Now, i have learned the FPR for automatics is set HIGHER then that of manuals. I got a whole fuel rail off a manual and thought i would switch it in so i would have the base fuel pressure that the ECU is set for. But now i hear that having higher fuel pressure can be a good thing because you can run more boost on smaller injectors. So should i keep the auto FPR and run a little rich but have a little more leway in the boost area, or run the manual FPR? Opinions?

Call Mitsu.

yeah, call mitsu. Those break easily.

higher fuel pressure is ok if you can lower the MAS signal via a SAFC. You will run rich during normal driving though. Mitsu has the connectors like everyone says. I have not seen them being black though. My stock 450's had an orangish color connectors. You will want to get new orings and insulators for the injectors also.

It probably isn't that much higher psi, the ecu should compensate for it.

^^^ thats what i was thinking. Long term fuel maps should lean me out.