you can run a flat tappet cam in a roller block with corret lifters and push rods

my roller block had a slider an I swaped up to a roller and stock roller lifters and push rods

pul the dist and turn it 180* and drop it back in

it either on or 180* out and can be wired to run that way

some times the vac can hits stuff so you would turn it 180* to gain more room to adjust it