FA code rear end

[jerry weidner]

The date code for a oct 65 built rear end case should be 10 xx xx correct? they did not skip sept correct?
Buy the way any have a FA rear code rear end caase Oct 65 or earlier.

Thanks
Jerry

[John H.]

Re: FA code rear end

Jerry -

Nope, they didn't skip September - should be 10 XX 65.

[Mark S. Lovejoy]

Re: FA code rear end

FA Rear end code = 3.70:1, Positraction, 4-Speed, 396

Should have caps on the output shafts not U-bolts.

[Mark P.]

Re: FA code rear end

My 66 427 has u bolts instead of the caps on one side. Anything besides correctness that I need to be concerned about? I know I'm opening myself up to "didn't you know that....?" comments or responses, but I really don't know if there is a serious issue with not having them correct or if the stress on a big block u-joint/shaft is proportionally greater to the extent of requiring the cap/bolt system as opposed to a u-bolt. (even if I'm babying it and not dropping the clutch at every stop light) Basically, what I'm saying is, if the General thought it was a good idea, should I just shut up and replace them and not question it? I know it would get dinged on judging, but with the u-joints working fine right now, I'm not too excited about going in and tearing it apart for correctness alone.

Where is a good source for the caps and bolts when I get them replaced? I've seen some of the suppliers with a "Call for price" comment in their sales information. Original vs. repro? Is it even an option?

I do appreciate any responses you're willing to offer. I've wondered about this in the past, and would love to know what the real story is.

Thanks for the help!
Mark

[Wayne M.]

Example of early '66 BB rear assembly date

6S100224, a Sept 8th S-body 450hp, reports 3.70 rear FA_7_15_65, which happens to be the same differential assembly date as on a 396 car with 3.70 gears produced (225 cars earlier) the last day of '65 production.

Just to show that sometimes these assy. dates don't always follow expected lead times.

[John H.]

Re: FA code rear end

Mark -

Paragon has the bolt-style caps for $35.00 each (need 2 per yoke), and the bolt kit for $10.00 per yoke (4 bolts). You'll also need a bolt-type yoke (about $140.00), and the diff has to come out and apart to replace it. It's been out and apart before, when someone replaced the original bolt-type yoke with a U-bolt-type yoke. Functionally, I wouldn't worry about it until the diff needs a rebuild.