I have a 440 in my 66 charger and my buddy has one in his 68 Coronet R/T amd YES it is fast and powerful.

Like everyone before me has stated, if it is post 73 then you'll need to do a few extra upgrades since that's the time emissions control came into effect and reeked havic on the big and powerful engines of yor. Being a 69 casting you are good to go.

Glad to have you in the 440 club