Yes, there is an adapter available to upgrade to the new ART-2000. Please see Southeast Aerospace's upgrade solution - (ART-2000 Upgrade flyer)

Southeast Aerospace exchanges are based on the return of an undamaged, economically repairable core unit with identical part number as the unit shipped to the customer. An "economically repairable" core is defined as one where the cost to repair/overhaul (or Repair Cap) does not exceed 80% of the original SV/OH exchange price billed. Should the Repair Cap exceed 80%, the customer will be billed the additional amount. In the event this amount exceeds the Outright Price for the unit, the customer would only be billed the difference between the Outright Price and SV/OH Exchange Price with the core returned as-is to the customer.

Here is an example of such a transaction:

$1000 Exchange Price charged to customer
$1000 x .8 = $800 Maximum Allowable core repair charge or Repair Cap

$2000 Cost to repair core unit
- $800 Less Core repair cap
---------
$1200 Additional billing amount.

2200.00 Total Cost of transaction

Please Note:
SEA offers exchange on new items as well. However, repair cap as indicated above is still based on SV/OH exchange price.

The Bendix/King RDR 2000 Installation Manual (006-00643-0007), on page 1-1 states:

"The ART 2000 can be installed as a replacement (with a connector change) for the RS 181A or the RS 811A in an existing RDS 81 or RDS 82 installation. If installed with an existing IN 812A, however, Vertical Profile and tracking are not supported by the IN 812A. If using an IN 182A that is not Vertical Profile compatible, the Vertical Profile feature of the ART will not be supported. IN 182A indicators with part numbers of 066-3084-10 and 066-3084-11 are not compatible with the RDR 2000 system."

In addition, there is a "RS-181A/811A to ART-2000 Harness Connector Replacement" diagram in the RDR 2000 Installation Manual on page 2-99, Figure 2-49.