I think from what I looked at on the site it has one thing wrong. They list two L code 383 and one is 290HP and one is 330HP.
The 2bbls I believer were 330HP and were offered in base model challengers only in 2bbl form, not 4bbl form.....but that has me thinking now if they did do it a 4bb 383 in just a challenger not and R/T....no I dont think they did.