retrifit roller lifters

i have a 355 sbc pre roller lifter block when i built it i put a flat hydraulic
lifter and cam. wondering if the retrofit roller lifters will work with a regular cam or do i have to get a retrofit cam as well?

Never put roller lifters on a flat-tappet cam, and vice versa. Lobes for a flat-tappet cam are "raked" (a slight angle) to insure the lifter will turn during operation. Roller cams are ground "flat" so the lifter CAN'T turn. The retainers (with the retro-fit, they use a bar) are there to keep the lifters in line with the lobe.

ok. thanks!