The LT4 is a strong motor, but don't try to compare a stock LT4 to the 4-cam, 32 valve, LT5! The LT5 is another beast altogether. Granted, the LT4 can be built up to be highly competitive (mine is a decent example), but then again, so can the LT5.
The ZR-1 is
still King of the Hill and I have no problem with that. That doesn't belittle the LT4 one little bit as it is still the best SBC (small block chevy) ever mass produced.