~たる form of a verb


Context: a boy is always been a head shorter than a friend of his, and he
always said:

> いつか、必ず抜いたるけんな

which I think I can quite understand ("Someday, I'm sure I'll surpass him"),
but not really, since the whole `抜いたるけんな` baffles me.

I did some research, and I found that `けん` [can stand for
`から`](https://japanese.stackexchange.com/questions/47511/%E3%81%91%E3%82%93-in-%E4%BD%90%E8%B3%80-dialect),
but I'm not sure this is the case (see later).

About `たる` I found a couple of questions
([this](https://japanese.stackexchange.com/questions/40891/please-help-me-
understand-this-%E3%81%9F%E3%82%8B) and
[this](https://japanese.stackexchange.com/questions/6985/meaning-
of-%E3%82%8B-in-%E5%95%8F%E3%82%8F%E3%82%8C%E3%81%9F%E3%82%8B)) which don't
quite seem to apply, since in the first the structure is different (`stem-たる`,
while above is `short past-る`), and in both is attributive, while above it
doesn't seem so (unless it's attributive to `けん`, in which case it doesn't
mean `から` and I don't understand it's meaning).

About `な` I think it's just and ending particle, maybe for emphasis.

