MKIV upper radiator hose will fit a MKIII if cut
 

My upper radiator hose (Gates) started to leak coolant when cold because the rubber had become stiffened after 11 years of use. It only leaked when it was cold as soon as it warmed up that problem went away using original Toyota spring clamps. I thought I would get another Gates or even Toyota hose if it was available online but what I found was that a MKIV Turbo upper radiator hose has the same inner diameter 30 mm As a MKIII plus it's longer on both ends. (See photos). I got a Toyota made MKIV Turbo upper radiator hose on eBay from genuinepartsplanet for $17.55 delivered ;which is competitive with Gates, plus it's an original Toyota part. At the time of this revised writing (10/19/18) there were 4 hoses left. If you need one, do a eBay search for the following which is the title:

GENUINE TOYOTA SUPRA RADIATOR UPPER HOSE 16571-46150

The Toyota MKIII part number is 16571-42010.

See the photos below for a comparison of the original Gates versus the MKIV hose before and after cutting. The MKIV hose is a little more right angular but I think it looks better. It does not interfere with the fan or the belt.

Thanks for the info. I need to replace my radiator hose also.