FPC shows availability of HD shocks, HD springs, HD torsion bars, and taxi-spec equipment for A-bodies. But now you've got me wondering even more about that TSB, which might have been written with reference to B-bodies. Nevertheless, the same sleeve is listed for A- and B-bodies in the '65 FPC, with a quantity of 2 (not 4) per car, and the TSB did definitely call for the sleeve to go in the rear-bushing location on each side.
I show the p/n in question (1857 840) is new for '62, where it is listed as 2 per car for B-bodies only. Same in '63 and '64. The first listing of this (or any) sleeve for A-bodies is in '65, and it continues in '66 and '67. I also checked '69, where it's still the same (2 per car for A- and B-bodies), only now it's called "SLEEVE, arm locking". Same applications in '70 and '71 and '72 ("SLEEVE, arm"). In '73 it's called out as 2 per car for A-bodies only, not for B or any other.