What is the normal considered time to pull these and do an inspection/replacement?

From my basic understanding glow plugs about 50,000 – 80,000 kms.

What is it for injectors?

Motor DZ30 Di

Brand new long motor, 500 kms. Just replaced the old one at 168k km as it had a head crack and cooked a few things.

New motor: NADS and glow plug timer set to 15 seconds. Also came with ceramic glow plugs, thanks to Nissan.

Also changed DMF to a single mass one, new heavy duty clutch and an all metal radiator, plus a few other minor mods.