Some examples where the Greek adjective, "πᾶς", is translated as WHOSOEVER in the KJV, in relation to salvation, and some other Versions
John 11:26, "And whosoever liveth and believeth in me shall never die. Believest thou this?"
John 12:46, "I am come a light into the world, that whosoever believeth on me should not abide in darkness"
Acts 2:21, "And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved"
Acts 10:43, "To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins"
Romans 10:11, "For the scripture saith, Whosoever believeth on him shall not be ashamed"
Romans 10:13, "For whosoever shall call upon the name of the Lord shall be saved"
Some of the other English Versions, use various words, that basically agree with the KJV's WHOSOEVER
ASV, NKJV, Websters, "whosoever"; NASB, WEB, "whoever"; ESV, NET "everyone"; NLT, NIV, "anyone"
There can be no doubt, that "πᾶς", is not restricted in its meaning to "all", and does also mean, ANYONE, WHOSOEVER, WHOEVER, EVERYONE", etc, etc.
Taking the NET Bible reading for John 3:16, "For this is the way God loved the world: He gave his one and only Son, so that everyone who believes in him will not perish but have eternal life". it is clear that "πᾶς ὁ πιστεύων", is here translated, "everyone who believes", who are from "τὸν κόσμον", the "entire human race"; as opposed to "ὁ δὲ μὴ πιστεύων", in verse 18, who are also from "τὸν κόσμον".
Some try to misrepresent what Jesus is saying here, by attaching "πᾶς", to those who "πιστεύων", and not to "τὸν κόσμον". What Jesus says is clear, "God so LOVES, with a SAVING LOVE, the ENTIRE HUMAN RACE". However, only those "who BELIEVE", from the ENTIRE HUMAN RACE, will be saved; and those "who DISBELIEVE", the ENTIRE HUMAN RACE, are already condemned.