gorilla penises are, on average, only 1-2 inches, for the sake of fairness, we'll decide to use 2 inches for kong.
We know that kong and godzilla are around the same size because of the trailer.
Gorillas are, on average, 5 feet tall, this makes kong (since they're both around 395 feet tall) 79 times the size of an average gorilla, this would mean that if kong is simply a scaled up gorilla with the same proportions, that kong has a 158 inch, or 13. 16666 repeating foot penis.
So to summarise, kong's penis is 13.2 feet (rounded up) long.
Now for godzilla.
This one was tough, as I don't believe godzilla is solely one real world animal, but in the old incarnations he was mutated from a "Godzillasaurus" which is a fake dinosaur loosely based on the tyrannosaurus rex, so I will be using the t-rex for my references.
There are colliding sources on the average penis size of a tyrannosaurus, with the lowest I've found being 10 inches, and the highest being 12 feet, lets assume godzilla is in the middle around 6 feet naturally. T-rexes had a height of around 17 feet, however, if we look at godzilla's we can see he is in a much more humanoid appearing stance, so i towuld be more accurate to measure with the t-rexes length from head to tail. t-rexes were 40 feet long, meaning godzilla is only about 10 times as big as a t-rex. to be exact, 9.87. For the sake of ease, i will round up to 10, i hope i can be forgiven for this.
Godzilla's penis is around 60 feet long.
TL;DR godzilla's penis is 60 feet, kong's is 13.2 feet, meaning godzilla's dick is 4.545 repeating times bigger then kong's
