[Jack21]

Think factory 351W roller blocks were made from '93 - '95 when the W engines were discontinued.

However, all the major cam grinders make retrofit roller cams to fit any year block. Comp uses standard roller lifters and a smaller base circle cam. Crane uses shorter lifters, and a standard base circle cam. All use the standard spider to hold the lifters in place.

When retrofitting a non-roller block for a roller cam, some machine work might be necessary on the block to properly fit the spider, and clearance the back of the lifter galley for lifter and bar clearance.