This air handler may be the one that physically fits the space. It does not allow that unit to achieve its highest ratings (14 SEER and loses a small amount of cooling capacity), but it is still a match fully supported by Trane. It won't qualify you for the 30% tax credit (up to $1500) but that may not apply in your situation since you aren't paying for the installation (insurance is). Many times more than one air handler can be paired with the same outdoor unit.

plwcdi

while you may be limited due to space considerations, look at the numbers. they are pathetic for such a nice system.
and these numbers will affect your operating cost and comfort.

see below.

1384029 Active Systems XL15I WEATHERTRON TRANE 4TWX5036A1 4TEE3F37B1 34800 11.80 14.00 37600 7.80 24000

I would discuss alternatives with the Trane dealer. the 39 air handler is much better-see if it will fit. get the measurements yourself.

another idea might be the recently introduced XR15 systems.

I would not do this without first exploring all alternatives including other brands.

IMO