Was the turbo 400 used behind 454 engine in 1989 suburbans?

No, the TH400 (Turbo Hydra-Matic 400) transmission was largely phased out of GM trucks by 1989. By that year, the 4L60E (a four-speed automatic overdrive) was the more common automatic transmission behind the 454ci engine in Chevrolet Suburbans. While you might find a very rare exception (perhaps a custom build or very early 1989 model), it's highly unlikely a factory-built 1989 Suburban with a 454 would have a TH400.