'66 Radio Speaker Mounting - 2 Screws Only?

[Gas_Pumps]

There are four mounting screw holes for the standard AM radio speaker. It appears that Ford only used two screws diagonally opposite. Is there a technical issue that four screws might warp the speaker frame or something or was it strictly a cost issue.

I just installed my aftermarket speaker with 4 screw. Did I screw up?

[farmerjohn]

I've only ever seen 2 screws used. Probably the bean counters saving hardware and time?

[Gas_Pumps]

Decided to use only the two screws. Four could warp speaker frame if dash is not perfectly flat. Also found out that adjusting the antenna tuner on the original radio is critical to best reception. 45 year old original radio works great.