You ask about the differences in the translations and you ask about resources.

The difference in translations is due to the underlying Greek text. The KJV is translated from the Received Text which is based (it is not exactly the same but it is based) on the Majority Text.

Most other translations are usually based on the Westcott and Hort text which gives very considerable weight to the Codex Sinaiticus and other early texts.

The best resource I know of to give a scholarly argument, based on massive achievement in the science of textual analysis is :

Dean Burgon 'Revisions Revised'. There is a kindle edition available on Amazon.

I read this book as a teenager in about 1969 and I have never departed from what I learned between its pages.

You ask about the differences in the translations and you ask about resources.

The difference in translations is due to the underlying Greek text. The KJV is translated from the Received Text which is based (it is not exactly the same but it is based) on the Majority Text. This text dates from the 1550s. [TR-Wikipedia] 1

Most other translations are usually based on the Westcott and Hort text which gives very considerable weight to the Codex Sinaiticus and other early texts. This text dated from about 1880.

The best resource I know of to give a scholarly argument, based on massive achievement in the science of textual analysis is :

Dean Burgon 'Revisions Revised'. There is a kindle edition available on Amazon.

I read this book as a teenager in about 1969 and I have never departed from what I learned between its pages.