In my experience the computer will simply shut down, due to a GPU power spike. This even happens with a 1300W PSU and a Quadro RTX A4500. Also, make sure that your new PSU will physically fit your chassis. On mine, for example, there is a slot which only fits that particular model.

I'm hoping that this model power supply does have the shut off protection feature like it seems your does... I can't find if this power supply in particular has it. I believe most quality power supplies shut off on overload rather than burn out or even worse, have potential voltage spikes.. I'm more hopeful seeing this unit had the fault lights on it so must have some sort of protection...

Hopefully a Dell rep may be able to share this Information on the oem power supply. I can't find it

In general, Dell power supplies are very good.  Although they don't advertise each and all of the protection features, when kicked in, the system would reboot to protect motherboard and components from getting damaged.

Gamers Nexus did a power supply review for G5 gaming system and the result was positive.  One can expect similar quality in professional models such as Precision workstations.  On a positive note, the 3630 uses standard ATX power supply and very easy to upgrade when needed.  The 460w PSU can safely support up to 180w graphics card.  For anything higher, it's better to upgrade it with a good or premium brands.

Seems the 4070 is a 200 W card and the model I'm looking at uses an eight pin connector so hopefully it will still be suitable

It will work, but it also will max out the 18A rail.  

@Chino de Oro​ so can I put rtx 2060 6gb graphics card without changing the power supply. I have a dell precision 3630 I5 9500 it has a 8 pin connector