Drum Measurement

["Joseph M. Shaw, II" <MikeIIDC@domain.elided>]

Digest Guys and Gals-

I've been typing back and forth with Gary about his possible purchase of
an old T'all.  I was warning him about brake drums.  I have the
seemingly rare 12x1 3/4" drums, and the last time I tried to track some
down about five years ago, it was a very expensive and time consuming
task.  I called all of the IH specialists I knew of then-I don't
remember all of the names, but they ranged from the guys in Oregon and
Washington state, to someone in Texas, Colorado, Illinois, Ohio, and a
junkyard or two in Indiana, as well as a IH junkyard in LA.  It still
took a couple of weeks to get one and it was damn expensive.  These
drums come up on the list at the parts store as being placed on '62-'67
2WD's, but mine is a '68 4X4.  Anyway, I told him to check what kind of
drums it has, because if he has these, it could be a pain, and an added
expense.  He was asking how to measure.  I am going to give him some
advice, and if I say anything that is wrong, please correct it so that
he gets the right info.  He really wants this truck and I want him to
have it, but I want him to know all of the facts first.

I think the measurement is simply diameter x depth.  12" across, x 1
3/4" deep.  The exterior depth will be a little more than this, I'm
assuming, as the pads themselves should be 1 3/4" "wide."  Therefore, if
you pop a wheel and measure a drum from the outside and it is 2", I
would assume that you actually have the 1 3/4" drum, as the steel is
cast pretty thick.  I would guess that you should plan on the outside
"depth" of the drum needing to be at least 1/4" thicker than the
measurement listed.  I cannot get out to measure mine right now, so if
anyone knows any better, please tell us now.
I also suggested that he could get all new brakes with new backing
plates, etc. and switch over to the more common sixed 11" x 2" drums, or
even try to do a disc conversion.  Does anyone have any info on this? 
What kind of additional cost are we getting into on this?  This is what
mechanics have always recommended with mine, but I am anal about trying
to keep it completely original.
If anyone knows more about this conversion and its costs, please speak
up, as I know Gary is hot after this truck and needs the info ASAP!

Thanks!

Michael