Shank positions of MTL unassembled MTL couplers?

[Ike the BN Freak]

2001 — centering spring in front of the pivot post, offset shank height, standard shank length.  Also referred to as 2003 at times.
2004 — centering spring in front of the pivot post, offset shank height, extended shank length.  At times packaged in combo with 2001.

Think the shanks are the other way, on the conversion page for the Kato SD40-2, says to use 2001s for tight radius curves.

[Doug G.]

The MT numbers can refer to a particular set or combination of couplers, not necessarily a unique coupler. The 2001 consists of one pair short shank couplers and one pair long shank couplers. The 2004 consists of two pair of short shank couplers. The couplers in both sets are identical except for the long shank length on one of the pairs in the 2001 set.

There has been much confusion on this as people wonder what the difference is between those two sets, thinking they have different numbers because the couplers are different when the 2001 and 2004 designations represent two different combinations of basically the same couplers.

Doug

[OldEastRR]

Aha -- the MTL chart gives me the answer. Apparently WOT and others are using the 1019, 1021 & 1022 as coupers in the bodies of their own coupler pockets. Thanks!