The flight lands at YVR 07:00 and takes off at 08:40. Do I need to take my check-in baggage out, go through pre-clearance and, check it back in? If so, would there be enough time? Would welcome any experiences and advice.
The answer to such questions will always be:
If the airline sold you that itinerary as a single ticket/trip, they think you can make it.
If DEL-YVR is delayed, you will be reaccommodated on a later YVR-LAX flight, of which there are several throughout the day.
You normally would not have to collect and re-check you bags at YVR provided you bag is properly tagged. Note, you may have to wait until your checked bag is transferred to CBP before you are allowed to approach Immigration (Passport Control). (I'm not exactly sure how this works in the terminal so pay attention.)