i was reading thru www.toysport.com
a while back, figured this might help you out...
"BUILDING THE ZZ ENGINES
The aluminum block is hefty and casted really clean. It will allow the engine to produce massive horsepower over stock. Dimensionally they are bigger than the 4AGE, the engine family it is superceding. Block strengthening is possible, by pinning the cylinders to stabilize the bores. The crank is a lightweight design and so are the rods. The crank and rods are casted really well, stress-relief and shot-peen- will produce parts that look forged.
The 2ZZGE has problems. Bent valves from missed shifts have been common. Sticking valve mechanism also cause unscheduled visits to the Toyota Dealers.
Toyota is addressing these problems currently. We have forged pistons in stock and .5mm os available with deeper valve reliefs and a .5 higher compression."
they also said that the GTS head, which is the GE head, is the "sports head", a natural for turbo