• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

18 spline 4 speed identification

John Milner

Well-Known Member
Local time
12:16 AM
Jun 2, 2021
Reaction score
I have this 18 spline 4 speed and I was wondering if anyone could help me out with the VIN stamping on the side to see what this came out of originally and if this was originally an 18 spline transmission. Thanks




The '823' extension housing is correct for a 68. The 68's stamped the last vin numbers on pad. Your 8G.. will be hard to track down as to a 440 MT car, but assume it did.
Certainly looks like a original 68 b body combo
Check the front bearing retainers bolt circle diameter. It should be 4.16". In 1968 and 1969, only 18 spline transmissions had that bolt circle, from the factory. That bolt circle was used with the 308 bearing, and only 18 spline transmissions used it in those years
Thanks everyone. I did not know that about the front bearing. This one does have the larger front bearing. Looks as if it all grew up together. I was a little curious if it came behind a Charger or GTX, and if it was a Hemi or 440 car but it doesn’t look as if there is a way to tell.
Starting in the 1970 model year the 308 bearing was used on some 23 spline transmissions as well. The 66-67 18 spline transmissions used the 307 bearing.
Auto Transport Service