Here are some choices of roller rocker arms for the Chevrolet 250:
Crower Enduro Stainless Steel 3/8" stud 1.75 ratio
Crower Enduro Stainless Steel 7/16" stud 1.75 ratio
Crower Enduro Aluminum 3/8" Stud 1.75 ratio
Crower Enduro Aluminum 7/16" Stud 1.75 ratio
Comp Cams Pro Magnum 7/16" Stud 1.7 ratio
Crane Aluminum Gold Race 3/8" Stud 1.7 ratio
Harland Sharp 3/8" Stud 1.75 ratio
Harland Sharp 7/16" Stud 1.75 ratio
