71 Fury heater core ( non a/c, non strato vent ) questions

[marko]

i need to replace the heater core in my 71 440 fury wagon, i havent pulled mine yet.
ive been looking on ebay and found a seller who has them; but in their notes it says :

Custom Suburban, Sport, Sport Suburban, Suburban; VIN: T, 4BBL, Natural; w/o AC, w/o Upper Level Vent Mfrlabel Heater Core

my car has the optional "strato vent" upper vents - was there really a different heater core for strato vent, non a/c cars ?
i do have a spare heater core for a regular 69 c body.......
tx for any advice,
mark in victoria, bc canada