The differences between the Textus Receptus and the other witnesses are really trivial (see below). The major difference is a simple reversal in word order. In verse 20, the Textus Receptus reads:
(a) και μετα ταυτα (b) ως ετεσιν τετρακοσιοις και πεντηκοντα
Lit. (a) "and after these things" (b) "about years four hundred and fifty ..."
Whereas the Codices read:
(b) ως ετεσιν τετρακοσιοις και πεντηκοντα (a) και μετα ταυτα
Lit. (b) "about years four hundred and fifty" (a) "and after these things"
The issue of the four-hundred fifty years relates not to the manuscripts - they are all consistent - but rather to punctuation, which was not in any ancient manuscript (as neither were verse numbers).
In the second edition of A Textual Commentary on the Greek New Testament, Bruce Metzger writes (p.358-59):
The problems of verses 19 and 20 are both textual and exegetical. The
Textus Receptus (following Db E P Ψ and most minuscules) speaks of the
period of the judges following the division of Canaan: “and after that
he gave unto them judges about the space of four hundred and fifty
years, until Samuel the prophet” (AV). On the other hand the
Alexandrian text transfers the temporal clause to the end of ver. 19,
and thus makes the four hundred fifty years cover a period prior to
the institution of the judges: “… when he had destroyed seven nations
in the land of Canaan, he gave them their land as an inheritance, for
about four hundred and fifty years. (20) And after that he gave them
judges until Samuel the prophet” (RSV).
The chronological reckoning involved in the reading of the Textus
Receptus agrees almost exactly with that of Josephus (443 years,
according to Antiquities, viii.iii.1), and both differ widely from 1
Kgs 6:1, where it is said that Solomon (who lived long after the
judges) began his temple in the four hundred and eightieth (so the
Hebrew text; but the Septuagint text reads four hundred and fortieth)
year after the Exodus. The reckoning that lies behind the Alexandrian
text evidently covers the four hundred years of the stay in Egypt
(ver. 17) plus the forty years in the wilderness (ver. 18), plus about
ten years for the distribution of the land (Jos 14).
On the surface, however, the Alexandrian text appears to limit the
four hundred fifty years to the time that passed between the division
of the land by Joshua and the institution of the judges. It was
probably in order to prevent the reader from drawing such an erroneous
conclusion that scribes transposed the temporal clause to the
following sentence, producing the reading of the Textus Receptus.
It may be added that when modern translators of the Alexandrian text
break up the one Greek sentence of verses 17, 18, and 19 into several
different sentences, it is almost inevitable that the reader will take
the temporal clause of ver. 19 as referring only to the final
sentence.
1550 Stephen's Textus Receptus
και καθελων εθνη επτα εν γη χανααν κατεκληροδοτησεν αυτοις την
γην αυτων
και μετα ταυτα ως ετεσιν τετρακοσιοις και πεντηκοντα εδωκεν κριτας εως σαμουηλ του προφητου
κακειθεν ητησαντο βασιλεα και εδωκεν αυτοις ο θεος τον σαουλ υιον κις
ανδρα εκ φυλης βενιαμιν ετη τεσσαρακοντα
I have boldfaced words that vary between manuscripts
Codex Siniaticus
και καθελων εθνη επτα εν γη χανααν κατεκληροδοτησεν την γην
αυτων
ως ετεσιν τετρακοσιοις και πεντηκοντα και μετα τουτα εδωκεν
κριτας εως σαμουηλ του προφητου
κακειθεν ητησαντο βασιλεα και εδωκεν αυτοις ο θεος τον σαουλ υιον
κις ανδρα εκ φυλης βενιαμιν ετη τεσσαρακοντα
Codex Alexandrinus
και καθελων εθνη επτα εν γη χανααν κατεκληροδοτησεν αυτοις την
γην αυτων
ως ετεσιν τετρακοσιοις και πεντηκοντα και μετα τουτα εδωκεν
κριτας εως σαμουηλ του προφητου
κακειθεν ητησαντο βασιλεα και εδωκεν αυτοις ο θεος τον σαουλ υιον
κις ανδρα εκ φυλης βενιαμιν ετη τεσσαρακοντα
Codex Vaticanus
και καθελων εθνη επτα εν γη χανααν κατεκληροδοτησεν αυτοις την
γην αυτων
ως ετεσιν τετρακοσιοις και πεντηκοντα και μετα τουτα εδωκεν
κριτας εως σαμουηλ του προφητου
κακειθεν ητησαντο βασιλεα και εδωκεν αυτοις ο θεος τον σαουλ υιον
κις ανδρα εκ φυλης βενιαμιν ετη τεσσαρακοντα