4 speed 26 spline vs 30 spline output

[NChap55]

Need some opinions. putting together a 383 dart. Can you get by okay with a 4 speed with a 26 spline output shaft or is the the 30 spline the only way to go. motor will be mildly warmed up (400 hp or so). Car will never see the dragstrip, have no plans to be dropping the hammer @ 5000rpm or so. Thanks in advance for any input.

 

[caferacerx]

fewer splines = stronger
mopar used the 18 spline box with hemi's and big blocks

 

[rklein383]

The 26 spline output shaft is smaller and weaker than the 30 spline unit. When Chrysler starting putting big blocks in the darts and barracudas in 1967, they upgraded the output shaft to the larger and stronger 30 spline unit.
Rod

 

[cudamark]

The 26 spline output shaft is smaller and weaker than the 30 spline unit. When Chrysler starting putting big blocks in the darts and barracudas in 1967, they upgraded the output shaft to the larger and stronger 30 spline unit.
Rod

Yup, but I've never seen an output shaft break on either one.

 

[caferacerx]

I was thinking of 23 and 18 spline input shafts duh

the 26 spline output shaft is the same as a 904
and the 30 spline is the same one used with a 727

 

[wayfarer]

383 and 400 used the 26 spline...why should you worry? I have the 23 in my 73RoadRunner with a warm 440 and have no issues or concerns. In fact it is the original trans for the car (400-4v) and I have never had to open it up...

Quit over thinking the issue......

 

[cudamark]

Big blocks transmissions all had the 30 spline output shaft (on a slip yoke trans) .....automatic or manual trans. It's the INPUT shafts were either 16 or 23 spline.