18 or 23 spline?

[MoparBill]

I have a 69 RoadRunner project and I'm not sure which 4 speed the car should have. It has a 383, D21 code trans and A31 rear axle on the fender tag. I don't have a build sheet. Should it have an 18 or 23 spline trans? Any help is much appreciated!

 

[shag766]

i am not a garu on this but from what i understand the 18 was a hemi and maybe a big 440 tranny. i am sure someone will know.

 

[lewtot184]

23 spline

 

[Cranky]

i am not a garu on this but from what i understand the 18 was a hemi and maybe a big 440 tranny. i am sure someone will know.

Yup....

 

[Meep-Meep]

Yes, the 383 got a 23 spline.

 

[63RedFury]

23 was standard with the 383.

 

[MoparBill]

I know this is a different question, but will a 23 spline hold up with a mild 440- 10:1 compression, 906 heads, stock intake, HP manifolds, moderate cam? Again, any input is appreciated.

 

[The 500 Foundation]

my convertible has a similiar set up, with dual 4 barrels,
and it has held up nicely for years.

 

[PAPATECH]

23 spline

I know this is a different question, but will a 23 spline hold up with a mild 440- 10:1 compression, 906 heads, stock intake, HP manifolds, moderate cam? Again, any input is appreciated.

hey bill ran a 23 spline for a long time in my 1969 roadrunner with a 440 put he car together back in 1977 had it for 5 years , sold it & bought it back six years ago , never had any problems with the 23 spline may be a weak link with slicks . papa.

 

[696pack]

23 spline should be good up to about 550 h.p.

 

[Meep-Meep]

One guy I know used to race a 68 Charger with slicks and he had a 23 spline. No issues as far as I know. The car ran 11's.