SBS6602A
(CG 3) 
(CG 39) - Replacement for
987D.
SBS8641Z
(BN SP) (CG 3)
This is a recent swap, took place only since about 2 weeks+ ago
according to my spottings. 6602A did went to Sv 3 together with
6601C for close to a month before this swap to replace 975M &
1971S.
But since 2 weeks+ ago, 6602A replaced 987D's ex-timings directly
on Sv 39 quite consistently. And in return, 8641Z replaced 6602A's
timings on Sv 3 by spottings.
If there's any changes, I'll update accordingly. But for now, this
should be correct for the foreseeable near future.
Cheers. 
6602A not even perm 3 in the first place.
6601C replaces 975M
6602A replaces 987D
8641Z replaces 1971S
