Yes, I did some comparisons between a reprint of an edition of the Great Bible printed in 1540 and the 1611 KJV. My 400 word count is based on comparisons in the book of Psalms, Proverbs, and Acts.
Some scholars had pointed out the fact that there were some differences because the Great Bible had followed the Latin Vulgate in some places.
John Eadie maintained that the Great Bible "has interspersed through it a great variety of paraphrastic and supplementary clauses from the Vulgate" (English Bible, p. 383). John Eadie also affirmed that “there are more than seventy such additions in the book of Psalms” (p. 385). Henry Swete noted that many of the peculiarities of the Psalms in the Great Bible may be traced to the Septuagint "through the Gallican Psalter incorporated in the Vulgate" (Introduction to O.T. in Greek, p. 99).
At the end of Psalm 13:6, the 1540 Great Bible added the following sentence: “Yea I will praise the name of the Lord the most high.” In Psalm 14, the Great Bible (also 1535 Coverdale's Bible) has three additional verses which are not in the KJV. These three verses from the Latin Vulgate are also in the Douay-Rheims Bible [numbered Psalm 13 in Douay-Rheims]. The 1540 Great Bible added words found in the Septuagint at Psalm 17:9 [“to take away my soul”]. In his introduction to a reprint of Coverdale's Bible, S. L. Greenslade observed that at Psalm 29:1, "Great 1540 adds to 1535 the Vulgate 'Bring young rams unto the Lord,' which has Septuagint but not Hebrew authority" (p. 24). At the end of Psalm 33:10, the 1540 edition included this extra phrase: “and casteth out the counsels of princes.” The 1540 Great Bible added the words “in the gates of the daughter Sion” at the end of Psalm 73. In Psalm 92:13 after “in the courts,” the 1540 Great Bible added the words “of the house.” The 1540 Great Bible added at the end of Psalm 111 the following: “Praise the Lord for the returning again of Aggeus and Zachary the prophets.” Another addition is found at the end of Psalm 132:4 [“neither the temples of my head to take any rest”]. An addition is also found in the 1540 Great Bible at the end of Psalm 134:1 [“even in the courts of the house of our God”]. At the end of Psalm 136, the 1540 Great Bible has the following addition or verse not in the KJV: “O gave thanks to the Lord of Lords, for his mercy endureth for ever.” In just these examples out of the seventy claimed additions, this edition of the Great Bible already has over one hundred forty words in Psalms that are not in the KJV.
The Great Bible has some other additions in the Old Testament not found in the KJV. At the end of Proverbs 12:11, the 1540 edition of the Great Bible has the following: “who so hath pleasure to continue at the wine, leaveth dishonour in his own dwelling.” After Proverbs 13:13, the 1540 Great Bible added the following sentence: “A deceitful son shall have no good: but a discreet servant shall do full well, and his way shall prosper.” After Proverbs 15:5, the following is found in the 1540 Great Bible: “Where righteousness is plentiful, there is very great power, but the imaginations of the ungodly shall be rooted out.” After Proverbs 15:27, it has this addition: “Through mercy and faith are sins purged, and through the fear of the Lord doth every one eschew evil.”
The edition of the Great Bible (1540) this author examined had many of the same additions mentioned in the paragraph about Coverdale's Duoglott (check Acts 4:25, 4:27, 5:15, 13:30, 14:7, 15:34c, 15:41c, 18:4, 23:24c, 24:17; Rom. 4:5c, 4:18c, 8:23, 12:17). Thus, the first authorized Bible (the Great Bible) has over one hundred words in just one New Testament book (Acts) which are not found in the third authorized Bible (the KJV).