Hola Amigo
 
 Lo he probado pero me devuelve la pagina en blanco, es un post lo que recibo probe de esta forma:  
 Código PHP:
      foreach ($_POST as $k => $v) {
                  print_r($_POST['producto'][$k]);
                  print_r($_POST['valor'][$k]);
                  print_r($_POST['unidad'][$k]);
                } 
    
   producto, valory unidad las variables de los input del formulario... 
 Volvi a cambiarlo, haciendo esto:  
 Código PHP:
      foreach ($_POST as $k => $v) {
                  echo "<pre>";
                  print_r($_POST['producto']);
                  print_r($_POST['valor']);
                  print_r($_POST['unidad']);
                  echo "</pre>";
                } 
    
   Me devuelve esto: 
 Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)
Array
(
    [0] => 1
    [1] => 25
    [2] => 30
)
Array
(
    [0] => 64356
    [1] => 64356
    [2] => 6456
)
Array
(
    [0] => m2
    [1] => m2
    [2] => m2
)