Welcome Elizabeth to FCBO!

[1970FuryConv]

Ao i ran it with make and model and it is telling me that only a 2 door hard top coupe can have the 383 cid 290 but mine is a 383 convertable

Welcome to the forum!
I also have a 1970 Fury III Convertible. Think they are great looking.
Your question: It's telling you that those engines were options with all the different models of Fury III. 1970 was the last year for the full size Fury convertible. All 1970 Fury convertibles were Fury III (not Gran Coupe/Sedan). Chrysler produced 1,952 Fury III convertibles in 1970.

 

[65sporty]

Welcome from the Mitten, these guy's are sure to help you out with all your questions