Differences in a Standard 727 and a HD 727

[69 Sleeper Bee]

I am following @3x2bee thread about a 6 pack transmission and seeing there is distinction between the 6 pack / hemi 727 and the HP 440 727 and was wondering about my 69 Coronet 440 with a 383-2 bbl engine that has an HD 727 ( code D32 )
What makes a HD 727 better than a standard 727 and would it be the same as an HP 440 - 727 ?

 

[R413]

Code D32 does not mean HD 727.

a 383 2bbl trans is just about the same as a 318 trans inside. 3 disc front clutch, 3 pinion planetaries. Low up shift governor.

 

[69 Sleeper Bee]

Code D32 does not mean HD 727.

a 383 2bbl trans is just about the same as a 318 trans inside. 3 disc front clutch, 3 pinion planetaries. Low up shift governor.

Ok now I am confused as the decoders said that it was a 3 Speed Auto Heavy Duty.

Here are 3 that I used. Not saying they are correct by any means but was wanting to confirm.

http://www.passion4mopars.com/1969-1971-Fender-Tag-Codes_b_25.html

https://www.stockmopar.com/mopar-fe...E&Vin3=139063&vin=WH23G9E139063&Submit=Decode

https://www.mopar1.us/6971codes.html

 

[Dave6T4]

The H.D. 727 has 4 pinion planetaries, front and back. Also 4 clutch drums, front and back (Hemi trans has 5 clutch drum and wider kick down band). These transmissions also had different spring pack in the front clutch than regular 727. The governor assembly had lighter weight and spring for higher upshifts. They usually had 3.8 ratio kick down lever instead of 2.9 or 3.2.

 

[dvw]

Any 727 is capable of holding 700 HP. a 4 disc high clutch, a good valve body, a deep pan will get you there. The only real differences are 3 to 4 pin planets (not needed), governor and valve body calibration, kick down lever ratio, and number of clutch and servo springs.
Doug

 

[oldkimmer]

Also the real HD and 440-6 and Hemi had a stronger input shaft. Easily recognizable by a dallop of yellow paint on the front of the shaft. Kim

 

[dvw]

Also the real HD and 440-6 and Hemi had a stronger input shaft. Easily recognizable by a dallop of yellow paint on the front of the shaft. Kim

I've been running the standard input shaft in mine for 10 years. 850+ passes.
Doug

 

[oldkimmer]

I've been running the standard input shaft in mine for 10 years. 850+ passes.
Doug

Same with almost every other racer on the planet by kim

 

[66Satellite47]

Sure never heard of harder input shafts. Over the years I've had many standard style 727's and a couple Hemi's & some HD style as parts cores. Mostly used the Turbo Action combination with their 5 disc into 4 drum combination. My last few I've done for customers have used Cope parts and his thin clutches and steels to get the 5 into 4, either 4.2 or 3.8 lever.
listen to dvw, knows his stuff.