Idler pulleys and brackets     63, 64, 65,  hiperformance Corvette C2

#21-28a idler pulley 63 early 327/ 340 +327/360hp (zinc) 
(63 early through sometime in Nov 63 )
mounts in lower hole below alternator bracket bolt

 #21-28b idler pulley (black)
 63 327/340 & 360 hp
 64  327/350hp,327/365,327/375 hp
65 327/375hp (FI)
mounts in lower hole below alternator bracket bolt
 

(NOT used on 66-67 ,  63-65 327-300 hp , 65 350hp )

see schematic diagram/catalog section 21    shop online/prices  -made in USA

#50-10a  idler arm 63-67 Corvette -Correct Repro with part # 3779185   & no grease fittings