When were the football-shaped speakers introduced in B-bodies?

['74 Sport]

I know some of you probably have (or had) a B-body car. I asked this question on FBBO a couple of days ago, but no reply so far. I really need to know as soon as possible.

The earlier B-body cars used the same dash speaker as our '67 -'76 A-bodies. I need to know if the '70 Coronet uses the same one, or is it the football-shaped speaker that drops in from the top of the dash after removing a grille, like those in the '70 Barracuda or '71 Challenger.

Thanks for any input,
Jerry

 

[green1]

If it drops in from the top, I would think it has screws showing.

 

['74 Sport]

That's what I mean... those football-shaped speakers are accessed by removing some screws on top of the dash and taking off a removable grille.