63 / 327/340/4:11 - Need Help Identifying Differential

[Thomas S.]

The pinion split on the rear of my 63 and I had plan on having it rebuilt, keeping the case and cover to keep things original. However, when I looked at the casting number it did not correspond to the 63-64 Technical Info Manual info.

The number I have is 8880303. Any clue on what that is out of?
The Assembly date does not appear to be formatted correctly or I'm reading it incorrectly. It is CE4 16 6. I know the CE matches up with the 4:11 but don't know about the numbers.
I couldn't find the casing date which is supposed to be on the driver's side output flange which is difficult to get to anyway.

Based on the VIN, My car is a early June 63 build

So it looks like the entire rear was replaced at some point and I will have to find a correct casing and cover.

[Joe L.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

The pinion split on the rear of my 63 and I had plan on having it rebuilt, keeping the case and cover to keep things original. However, when I looked at the casting number it did not correspond to the 63-64 Technical Info Manual info.

The number I have is 8880303. Any clue on what that is out of?
The Assembly date does not appear to be formatted correctly or I'm reading it incorrectly. It is CE4 16 6. I know the CE matches up with the 4:11 but don't know about the numbers.
I couldn't find the casing date which is supposed to be on the driver's side output flange which is difficult to get to anyway.

Based on the VIN, My car is a early June 63 build

So it looks like the entire rear was replaced at some point and I will have to find a correct casing and cover.

Thomas------


I think you've got the correct, original unit.

The casting number is 3830303. I know it doesn't look like that, but that's what it is. This is the correct casting number for a 1963.

The 4 16 decodes th April, 16. That's the assembly date of the unit.

What you're reading as the last 6 is, I believe 63. The 3 is not fully stamped. This, of course, represents the year of manufacture. It's a bit unusual for a 2 or, even, 1 digit year coding on differential units but, as I've said before, there are lots of deviations from normal on these differential stampings.

[Richard G.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Here is picture of another known 1963 4;11 differential.
I failed to find the picture I have of the stamping.

[Bob R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Here's a photo of my 63 rear diff. it's a little difficult to read but CJ 5 2 63 for my may 14 built car. The rear end casting date was December 22, 62 probably because CJ 3:08 was not a very common ratio.

[Gary R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Tom
63-4 carriers were different then later ones. The front hole for the snubber bracket should be tapped 7/16-14 as shown in Rich's picture. The top 2 cover bolt holes were through holes, the bearing caps inside were wide with tabs, 5 line hex bolts used. The cover was not dated, used machined threads for the large square plug, the vents were steel, and the posi tags were round metal.

Shearing the pinion was one weak area in these diff's, the other was with the weak DANA posi's. I just built an original 64 and had to replace the posi, gears, and the pinion yoke. You will have to do the same. Your axles should be hardened and in the 190" range from the face to snap ring.

[Thomas S.]

[Gary R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Tom
If your guy was referring to Muncie gears maybe. If he was referring to vette 63-79 ring and pinion sets he has no clue so you might want to see just how he is planning on rebuilding it. Also the diffs are different between c1 and c2- another red flag statement. Keep in mind many places, including catalog vendors, say they rebuild these diff's but in fact order them from a rebuilder. What is sent out may or may not be what you expect.
Good luck.

[Bob W.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Thomas, Send your rear to Gary Ramadei he is one of best rebuilders out their.


Bob

[Joe L.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

I don’t plan on rebuilding the rear myself. I’ve been told by my mechanic (c1&c2 corvettes only) that the best gears come out of Italy now a days. Obviously don’t want to have to do this again so I’m interested in your opinion on sourcing.

Thomas------

I agree with Gary. I don't know of any Italian-manufactured rear gears for Corvettes. They do make them for Muncie transmissions, though. However, I don't rule out the possibility that there are now Italian-manufactured rear gears. Masiero S. A., the manufacturer of the Muncie gears, is one of the largest gear manufacturers in the world. So, I suppose it's possible they have recently gotten into the Corvette rear gear manufacturing. If so, though, I'd like to know with certainty about it.

Coincidentally, I am in Italy right now but I can't check with Masiero.

[Ed S.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Thomas, Send your rear to Gary Ramadei he is one of best rebuilders out their.


Bob

Best advise in this thread yet. Send your diff to Gary. He will make it right - you will be very happy. Respectfully, one very satisfied customer.

[Gary R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Thanks guys.

[Gary R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Joe, Tom
To my knowledge, to date, their are just 4 suppliers for new 63-79 differential gears. I have not heard of any of them being made in Italy. India or China is what I was told but who knows today.

1- Richmonds- imported
2- Motive- owned by the same company that owns Richmond- imported
3- Yukon- Randy's brand- imported
4- Tom's - USA made in IL by US Gear and the Best. The problem is Tom died last January and I don't know if there are any new gears left in stock, most have been sold out. Tom would have them made in 200 piece lots so it is unknown if that will continue now. Rumor has it US Gear will now market these directly but I don't have any info on that. Tom had exclusive rights with them on this product. Tom told me prior to getting sick he was told they are going to 2 cut gears in place of the 5 cut and he wasn't happy about that. I advised everyone who asked me about gears to buy them while they still could and those that did were wise since the pricing on them has gone up if you find a set. The last lot of the 5 cut I saw were dated 2016.

[Thomas S.]

[Gary R.]

Re: 63 / 327/340/4:11 - Need Help Identifying Differential

Hi Tom
You may be correct that Motive has some Italian gears I have lost track of them since they would not be what I would use or recommend.

Also just to be clear, I was not fishing for work. I am booked out months in advance,I just wanted to make sure you have the options in front of you when make a decision. I don't know who your guy is and really don't need to know but I can say I have repaired plenty of work from rebuilders over the years, especially the recent years. It is in your best interest to know what you have before you proceed, if nothing else trust me on this.