Sounds like you own a really rare and cool car.

The "N" code and E63 on the fender tag only tell you the car came with a 383-4bbl; it does not tell you which version, 330 horse or 335 horse, the car actually recieved. Many sources incorrectly list the 68 and 69 H code and the 70 N code as the HP version of the 383.

You need the broadcast sheet to know which engine assembly was installed.

"L" is the code for the 2bbl 383. I don't think I've seen a source that lists the "L" code for a 383-4bbl 330 horse car.