Anyone out there know where I can get 4 5H4903 seal assy, for the torque convertor 

Hi, tmoline.
If Cat can't supply - which would surprise me - try a bearing service company as they often stock seals as well. If they are any good, they ought to be able to cross reference the part # - and probably cheaper too.

Just my 0.02.

spare.avspart.com/caterpillar/seal/5h4903/

Try here...
www.machinerytrader.com/parts/search?Par...903&SearchType=Start.

Conman equip is a joke! Who wants a used seal? they never have what they list either.

if you google search the part number you can often find the nsn or national stock number as many of these machines where used either by the military or us parks service, forest service or the federal highways dept.
this is helpful with bearings, gears, and oil seals as most of that stuff wasnt bespoke but was off the shelf from companies like hyatt, timken and chicago rawhide.
the nsn can show what other makes and models used those parts. sometimes it will also show updated part numbers and as the dealers dont always have listings in the catalog for the older equipment they can have info if the pn has updated.

cat has a listing on parts.cat have you called your local dealer. that seal fits the d9E, 583h pipe layer and the d353c industrial engine.
and yes like deas suggested you can also try a bearing supplies joint sometimes they can crossmatch part numbers. if you have the old seal they can often measure it and match one up. that if you get it out with out completely destroying it. also it might have the manufacturers part number on it. thats often the case with bearings and seals that are off the shelf. and it canbe cheaper as you dont pay for someone to put it in a yellow box or a bag with a fancy sticker.

The listing on parts.cat.com is notated as "Indirect replacement available contact dealer" which seems to be Cats code for "Not available"

That part number is not for the lip seal it is for the entire seal assembly. Do you need the entire seal assembly or just the lip seal? The lip seal is still available part number 5P-2376 which was 5H4894.
According to the manual only two are needed per torque converter.

cat can't supply and it is a carbon seal no match up

tried them