Function PlayerTextDrawLetterSize sets the width and height of the letters in a player-textdraw.
Function PlayerTextDrawLetterSize was added in 0.3e and will not work in earlier versions!
When using this function purely for the benefit of affecting the textdraw box, multiply 'Y' by 0.135 to convert to TextDrawTextSize-like measurements.
Fonts appear to look the best with an X to Y ratio of 1 to 4 (e.g. if x is 0.5 then y should be 2).

(playerid, PlayerText:text, Float:x, Float:y)
int playerid The ID of the player whose player-textdraw to set the letter size of.
int text The ID of the player-textdraw to change the letter size of.
float X Width of a char.
float Y Height of a char.

Return Values:
This function does not return any specific values.

MyTextDraw = CreatePlayerTextDraw(playerid, 100.0, 33.0,"Example TextDraw");
PlayerTextDrawLetterSize(playerid, MyTextDraw, 3.2 ,5.1);

Related Functions
The following functions may be useful, as they are related to this function in one way or another.