If you take the both vehicles -minimum- curb weight, the GX is about 900 Lbs heavier than the 4Runner. Given the 4Runner and the LX400 have the same engine, the LX will be significantly slower. If you put the V8 in there, it is a different story. Most sites have put the 4Runner 0-60 time as significantly higher:
Toyota 0-60 Times & Toyota Quarter Mile Times | New Toyota Camry, 2013 Corolla LE, Prius 0-60, TRD Tundra, Supra Turbo and 2014 Toyota RAV4 0 to 60 stats! Other reviews come in right around this number. Honestly the 4Runner is not a "fast" vehicle, but it's a giant, off road ready, body on frame SUV. If it was fast, it would get 12mpg (and we would all be arguing about how shitty the millage is). I really don't understand how people can complain about the power output for general driving conditions. If your not towing, then it has more than enough power to get you everywhere you need to be. My other car made 110hp, at sea level, when it was new. 5,500 Ft and 200k miles later, it still gets me around just fine.