Way back in 2009, the somewhat-and-possibly-unjustly-reputationally-tarnished James
Number Appearing: 1d4+4
% in Lair: 10%
Armor Class: 6
Hit Dice: 9
Attacks: 4 claws (1d4+2), 1 bite (1d8+1)
Hoard Class: XX
The girallon is a fifteen-foot-tall albino ape-like creature, lacking hair on its body, except for its head, which also possesses a large, fanged mouth. A girallon has six limbs, the middle set of which can be used either as arms or as legs, depending on the circumstances. These creatures are strong and dexterous and possess remarkable intelligence, with some of them even able to craft crude weapons and other implements. Girallons typically live in small family groups led by a dominant male. Fortunately, girallons are rarely encountered, as they prefer to dwell in out of the way places, particularly the subterranean ruins of past civilizations. Girallons possess infravision of up to 60 feet.
I think it's too powerful, because I see girallons as being -- basically -- smaller than this. They are specifically only 8 feet tall and are described as being cousins of the gorilla. In other words, I think what James did is very cool, but that he should have named it a "White Ape-Thing of Mars" instead of tacking on the name of an existing, less powerful, creature.
I stumbled across girallons recently because they figure into one of the adventures in the Razor Coast books that are being produced for Frog God Games. I had to prepare a converted Swords & Wizardry version of the girallon. How to go about it? Well, the first thing was to take a look at James's version, and I rejected it for the foregoing reasons, and the fact that the author in the Razor Coast adventure had definitely not treated it as a 15ft tall creature. The numbers were just too large for that to work. Basically we're seeing the conversion being pushed in a particular direction by the relative power levels of 3e/PFRPG creatures to one another. If you diverge too far from the web-like network of relative strength in the SRD, you end up creating problems for yourself later on, if you do lots of retro-conversions to old school. I like to think of this kind of backwards conversion as a SWitchback, since it's a neat little use of SW, when I use Swords & Wizardry ... yeah, I know, it's totally cheesy, but DO I NEED TO REFER YOU TO SIMON PEGG'S DEFENCE OF NERDS? Do I? I didn't think so, because if you've read this far you are a nerd like me. Just sayin',
That was a digression. Mea culpa.
Let's get back to the topic of four-armed apes, and ignore how that's a sentence you wouldn't really expect yourself to be writing or reading in a "normal" life. Four-armed apes. This is what I decided to use for my girallons:
Hit Dice: 5
Armor Class: 6 
Attacks: 4 hands (1d4), bite (1d8)
Saving Throw: 12
Special: hug and rend
Number Encountered: One, 1d4, or 1d10+5
Challenge Level/XP: 5/240
Girallons are savage, magical cousins of the gorilla, with four arms rather than two. When moving on the ground rather than through the trees, a girallon walks on its legs and lower arms. An adult girallon is about 8 feet tall, broad-chested, and covered in thick, pure white fur. It weighs about 800 pounds.
Girallons live in troops led by a dominant male. Solitary girallons are usually young males looking to start their own troop. Girallons are very territorial and tend to attack intruders without warning, including strangers of their own kind. Groups of girallons may attack in a line to drive prey toward a cliff or other hazard, or quietly form a ring around their target and suddenly close in.
Stat block for Swords & Wizardry:
Girallon: HD 5; AC 6; Atk 4 hands(1d4), bite (1d8); Move 12; Save 12; AL N; CL/XP 5/240; Special: hug& rend.