Different variants of JZ series come in cars like Cressida, Crown, Supra etc. I suppose the 1JZ and 2JZ are more economical engines than 1KZ, if not more torque producing. Not sure about 3JZ though.
"The Toyota JZ engine family is a series of inline-6 automobile engines. A replacement for the M-series inline-6 engines, the JZ engines were 24-valve DOHC engines. The JZ engine was offered in 2.5 and 3.0 litre versions."
Source: Toyota JZ engine - Wikipedia, the free encyclopedia