Go to this website and enter your vin #
http://www.toyodiy.com
Search for heater hose and you should come up with the page in the link below.
http://www.toyodiy.com/parts/p_U_1990_TOYOTA_SUPRA_MA70L-BLPVZA_8716.html?hl=87245A
Toyota Part # 87245-1B251 This is for a left hand drive Supra (NATO US)
The hose connects to the heater water union at the back of the head, part #90401-2204
