Howdy
I run at least a 5-40 synthetic(winter) in all my diesels and most have a 15-40 or 20-50 synthetic year around. The exception is my VW.
The oil pressures you are getting can be typical for these engines especially if you are running a thinner oil.
My 1996 with an unknown rebuild gets about the same as yours with a 5-40 oil. With a 20-50 I added 7-10PSI.
It makes me much happier.
Do a search on this forum for oil pressure and you will get all kinds of info and ideas.
1996 Chvy 3500 CCDWLB 6.5 Heathed, NO vac, marine injctrs, ARB bumper, BIG pipe, 3" lift, bright lights, bypass oil system.
1986 Chvy 6.2 M1009 blazer RAM AIR, Headers, Custom interior
2001 Chinook RV, V10 gas
1974 John Deere 1530 diesel tractor
1993 John Deere 455 Diesel lawn mower
1967 GTO, 1989 Honda Transalp
2009 VW Jetta TDI, flashed and piped, 6speed, fun car!
1998 6.5 suburban, stock, daughter's
1993 6.5 3500 CCSWLB GM8, Heathed, big exhaust, gauges, Son's
1984 6.2 ATS turbo 3500, SCDWLB - Son's
3 kids, 1 wife, 1 dog
Gunsmith, Tactics Instructor, Fabricator USMC 87-93 Semper Fi!