I'd bet a nickel that Greg T has nailed it, Bullet Racing. According to what I see on their site, this would be a hydraulic flat tappet cam. If it were a roller, it would have a HR designation.
Looking up a Crane cam with close to the same specs as the BR cam, I find the following information for parts to be used with that grind. The first two choices listed will fit into the stock OEM spring seats. The third spring shown here will require seat machining to increase diameter of the seat.
Springs, Crane 96802-16, retainers 99915-16, locks 99097-1
Crane Single Valve Springs 96802-16 - SummitRacing.com
(1.260" spring seat diameter)
Springs, Crane 99846-16, retainers 99944-16, locks 99094-1
Crane Single Valve Springs 99846-16 - SummitRacing.com
(1.255" spring seat diameter)
Springs, Crane 99838-16, retainers 99969-16, locks 99094-1
Crane Double Valve Springs 99838-16 - SummitRacing.com
(1.465" spring seat diameter)