OK the streamline strut was 1.6 inches major diameter .049 thick 4130 I
  think.
  The top plate was also .049 thick 4130.

  The welded on lower mounting tube had the two mini cooper engine strut
  rubber
  bushings.

  These 4130 items were heat treated to Rockwell C 64 after welding which was
  important. Failure to do so may result in a failed wing.

  The secret to these was as the car braked the wing would move forward
  slightly
  increase the angle of attack and the down force. As the car accelerated
  the wing
  would move back decreasing the angle of attack and the drag. Some people
  defeated this feature by adding unnecessary drag struts.

  The lateral loads on the wing were taken by the triangular plates welded
  to the
  top of the struts acting as dual leaf springs. 1/4 inch or 5/16 inch Bolts
  went up into the wing spar where nut plates were located. Rubber washers were
  used to
  give a bit of angular freedom. This would only work if the wing was super
  light  weight which it was due to the use of .016 thick 7075 T6 skin and .020
  5052 H32
  corrugated spar. Of course there was an angle adjusting link behind the
  strut.  The wing was not flush riveted as the induced drag was far higher than the
  skin friction drag. Monel pop rivets were used.

  The flexibility this provided was absolutely necessary as the top of the
  hub  carrier would move from side to side as the wheels went over a bump or the
  car rolled slightly in a high G turn.

  Some people attempted to copy it but they missed some of the important
  details.

  BTW  Dozens of Formula A cars and several CanAm cars used wings supplied
   by me using this design for many races. No wing failures occurred.

  Paul Lamar