Part # question - 4:78 ring and pinion

Did Buick ever make a 4.78:1 ring and pinion gear set? Can someone help decipher the following info?

I have a set with the following part # stamped on the ring gear:
1387123 43 9 GMO

Stamping for the pinion: 13867474 GMC 9 A

Can these part numbers be found in the Buick Chassis and Body parts catalog?

 

Yes they did. Somewhere in some of my Buick Stg2 literature it list the 4:78 gear/pinion part numbers.
Buick also made 4:30 gear sets for there 8.2. I have a set of each.

 

The original owner of my stage 1 installed 4:30 gears back in the late 70s. Here’s a picture of the original box with the part number Plus pictures of the original 3:64 ring and pinion.

 

Let me know if you ever want to sell the 4.30's. Optimally I'd like to find 3.91 but 4.30 might be better.

Same if you ever go back to 3.64 & want to sell the 4.30's I'd be interested.

 

Guy, any chance you could post the sales literature that speaks to the 4:78 gears?

 

I show part number for 1971 - 72 4.78:1 gearset as 1394307. Unfortunately the manual doesn't list individual gear numbers because they were always sold as a set.

Devon

 

Sure! Have all that stuff in a safe in my shop. Give me a couple days.