I can't tell what this tail housing number 3846489 is for ? anyone know? Vince
are you sure its not 3846429 ??
It's not a very good picture but here it is.
The "429" housing was widely used up to 1965 but after that mainly for non-Chevrolet applications. Think Pontiac, Oldsmobile and Buick. It has a driver's side speedometer output.
Most Chevrolets used the "584" tailhousing 1965-1970 which has a passenger side speedometer output.
Check the rest of the numbers on it. Like the main case casting number and any stamped letters/numbers for more information. Post it if you want and I can try to help.
No pictures of the gears. Ebay ad says, Muncie M22 / M20 close ratio 4 sp. VERY RARE!! :o
No drain plug. 2 rings on the input shaft. M20.
Assembly date starts with P9 so it is for the 1969 model year. I did not see a partial VIN but my guess most likely from a GTO based on the shifter mount.