How to tell if my torqueflite transmission is numbers matching

[monaco66coupe]

that vin shows with the L to be a 440HP trans, that is a valuable unit.

 

[MarkLevi]

...the L to be a 440HP trans,

Concur. In '69, "L" would be the HP 375hp "TNT" Chrysler engine; the "standard" 350hp 440 would have been a "K". Transmission part number on the pan rail should be 2892 093.
This transmission had fairly wide usage:
Late 68 (after March 15, 1968) / all 69 Belvedere, Coronet and Charger with 440
Late 68/69 Polara, Monaco, Fury, 300, New Yorker with 440 HP
Late 68/69 Roadrunner and Superbee with 335hp 383 HP

 

[MarkLevi]

I know it's been almost a decade but was it numbers matching?

Based on this photo with the conspicuously-missing matching VIN stamp on the trans flange, and the "new" bolt/washer, I'd be pretty confident this is not the original. Maybe OP is still around to confirm/deny? @JOMIDABR

 

[monaco66coupe]

early HP in 68 would be 2801541 for the 440HP,, same as 1967.
what is your engine size?