I ran a set of Cranes for years on the street and never had the first problem, in several motors. Depending on the make of the motor they were a factory install in the Cobra Mustangs 5.0 89-93 and will fit under factory valve covers. But you have to use the modern pedestal mount heads.
Umm...details man, details !!! Street only engine, combination, race street engine ?? Brand engine ?? You mention street (but no brand), the Crower stainless is the only rocker I'd run on the street. I've tried others (big and small Chevrolet), always gone back to the Crower, Stainless. Mike
The best systems are T&D and Jessel shaft mounts…no question about it. They both offer a “Sportsman” series. No poly lock or bracing required. They fit under lower rocker covers. Rarely need adjustments. I bought a set of T&D’s for my sons 422” dirt car engine because I was tired of resetting gaps. At the time they were $900 and I’d buy them again.
^^^X2 on high spring pressure (shaft rockers ) @ 9,000 rpms BBC I have ran Comp SS rocker on 6-6500 rpms ,& also H-Sharp around 6,500-6,800 street use with out any issue. SBC/BBC