Re: [Chevelle-List] 12 bolt rear question

[Z16CHEVELLEGUY]

thanks Greg:
this is a complicated issue. it was my understanding all larger HP (300 and 350 HP) 64 and 65 had 12 bolts. my first 65 was a 283 / four speed car and it had a 12 bolt. all z16s had 12 bolt but they were full size car (impalas) cut down to fit. somewhere i have an article that tells which should have a 12 bolt and which should have a 10 bolt. personally i have never seen a 64 with a 12 bolt.the 12 bolt for 64-67 is getting harder to find everyday.i do know that it was not a mandatory item for an SS.
after writing the above i found this in one of my books.
in 1965 all 6 cylinder and 283 (i know my 283 car had a 12 bolt) models were to receive the 10 bolt axle, while all 327 (250-275-300-350 HP) cars were to receive the 12 bolt. in 66 and 67 the 6 , 283 , 327/275 HP received the 10 bolt while all 327/350 (l-79s) and SS 396 cars received the 12 bolt.
the special run of 65 12 bolts rear ends built for the z16 were the same width as a standard 12 bolt. these axles are actually a Chevrolet passenger car heavy duty 12 bolt differential with 1/2 ton capacity wheel bearings.the passenger axles and tubes were shortened to fit the chevelle suspension. the carrier was a heavy duty differential with the large 8,875 ring gear.
                                                                        Larry