heater core .... puzzling 68 GTX

[rakort]

Is there some difference in a heater core for a 68 GTX 440 vs for example a satellite or roadrunner? Every time I look up a heater core for a 68 GTX 440 most sites are saying that they don't offer one or it won't fit the GTX. Looking at the pictures the ones that are offered for non-GTX cars look very similar.

 

[Cranky]

I've never heard of them being different......

 

[mac]

for 1966 through 1969 b bodies non a/c use part number 399101. it is the same for all those years no matter the engine.