Big block 727 decoding help

[73 Duster_forever 73]

I trying to figure out the past of this 727, any help is greatly appreciated.

 

[junkyardhero]

if that number clocks as 4039539 then it's a 78 400/440, long HD extension and rear timing hole

 

[73 Duster_forever 73]

if that number clocks as 4039539 then it's a 78 400/440, long HD extension and rear timing hole

What does the long hd mean and what does the rear timing hole do? Also the guy I got it from said he pulled it from a police interceptor, I do not remember the model. Would you be able to know if this is true.
Thank you

 

[townsend]

Can you give us all the numbers in your photo.
Some are hard to read.

 

[73 Duster_forever 73]

Can you give us all the numbers in your photo.
Some are hard to read.

Pk4039539 5835 0204

 

[townsend]

1978 Chrysler parts catalog shows it's from a 1978 Ramcharger or Conventional cab pickup with 400 or 440 engine with 727 transmission and long heavy duty extension.
Date code 5835 is July 19 1977.