TM 9-2320-364-34-4C-33C-34. OIL COOLER TEST PLATE.Fabricate oil cooler test plate from 3/8 in. (9.525 mm) thick mild steel stock.a.Using oil cooler gasket for template, cut a steel plate 9 5/16 in. (236 mm) by 10 7/16 in. (265 mm).b.Drill ten 3/8 in. (9.525 mm) diameter holes where shown.c.Drill 7/16 in. (11 mm) diameter hole where shown and tap to fit 1/2 in. NPT fitting.d.File off rough edges.e.Paint as required.