Presuming manual without the atf cooler in bottom ?
Anyhoo, doubtful if you can source an oem due to age of truck, but there are loads of companies supplying aluminium ones. Milners as of a few years ago no longer have them and Roughtrax dont list them either.
They are shown on Amayama and Partsouq diagrams, but you would need to check stock.
Try a radiator repair company, they may be able to repair/recore yours, or have one that fits.