If you say gorilla, you are insane. Let’s look at some basic stats. The average weight of a gorilla is 135 to 180 kg (300 to 400 lb), 600lbs max (obese at the zoo). The average weight of a grizzly is 180–360 kg (400–790 lb) and up to 1500 lbs! The bear absolutely has the weight advantage. Even if half of it is fat, it is still an amazing advantage.
Now let’s talk speed. The grizzly can run up to 56 km/h (34 mph). The gorilla clocks in at around 40 km/h (25 mph). The bear again has an amazing advantage of about 30% speed. Not bad for being a fat ass.
Now people always bring up jaw strength because the gorilla has a stronger bite. The gorilla has a 1300 psi bite while the grizzly has a 1200 psi bite. We are talking an 8% difference. Practically the same, yet the bear has way more protection. That is like saying "Guy A has a 4 ft sword and Guy B has a 3.5 ft sword and full body armor, who would win?".
The bear doesn’t only have teeth. It has a giant set of claws that would knock your head clean off. There are videos of bears killing moose with a hit to the head. One hit and at a minimum that gorilla would be totally dazed and have multiple lacerations. The gorilla has another serious disadvantage here.
The gorilla does have grip, which the bear does not, but that will not help in a fight with the bear unless the gorilla is wielding a weapon. The gorilla also has a much higher percentage of muscle than the bear, but that isn’t a good thing in a fight where lacerations are common. Look at how the gladiators were built as an example.
Any other statistics needed? The bear is the clear winner here in my opinion, and we are only talking about normal grizzlies. Not brown bears or Kodiaks. Hell, polar bears are easily twice as large as grizzlies with a maximum weight found to be 1002 kg or 2,209 lbs.
So what do you think? Gorilla or Grizzly Bear?