Questions regarding rear Heater Core interchangeability

[Hildago]

I have a 1987 4wd van. The car had coolant leaking problems when I got it, and I suspect the previous owner may have used Bars Leak, with the pellets to try and fix the problem, and it clogged the rear heater core ( the little radiator unit that heats the rear part of the car ). The front heater core never worked either, but I know they are much harder to change out, as they are buried in the front dash. I have a question or two regarding this dilemma

Does anyone know if other years models are basically the same and can be used in this model/year ?? ( ie are they interchangeable )

Secondly, any idea whether rear wheel drive models of the same year ( or other years ) have the exact same heater models ( they may well ),
or same thing, are there some other years of the RWD models may be interchangeable ???

Thanks for any input.

[llamavan]

There are a surprising number of heater core numbers even within years, but none are 4WD-specific. The differences (per Toyota) are "with AAC" and "Cold Spec" aka "Heavy Heater". They all mount into the same housing, so in theory they are all interchangeable ... but it's quite possible the A/C versions are reconfigured to accommodate the A/C.

Gwen

[SeattleSquatch]

There are a surprising number of heater core numbers even within years, but none are 4WD-specific. The differences (per Toyota) are "with AAC" and "Cold Spec" aka "Heavy Heater". They all mount into the same housing, so in theory they are all interchangeable ... but it's quite possible the A/C versions are reconfigured to accommodate the A/C.

Gwen

Does anyone know more about the Cold Spec ("Heavy Heater") versions? Is it just a beefier core that fits in same housing? Are more parts needed up the line to convert to Cold Spec (bigger blower, different controls, etc)?

I'm in the mountains alot and my current heat isn't cutting it. I drive an 87 4x4 no-AC. I found Cold Spec cores (front & back) at junkyakd. I'd like to re-core and install but want to make sure not missing something else in whole heating system before dishing out the cash for the re-cores!

Thanks!