i would like some opinions on the best oil to use when replacing the f350 7.3L turbo diesel oil

What year, and when you say "best", do you mean at any price, or "best oil" under $10/gallon?

well i hear the blue bottled chevron is good

i have a 92 turbo diesel f350 7.3L

well i hear the blue bottled chevron is good

i have a 92 turbo diesel f350 7.3L

The DELO oil (from chevron, I think) is good. My preferred choice is the Rotella-T made by shell. This is used in alot of the big semis.

what about the mobil1 blend?

Delvac 1 (Mobil 1 for Diesels) is VERY good oil.

15w40 rotella T is best all around. Can be bought anywhere in the USA and provides great protection.