How much lift are you wanting to run?
Two of my sons run the magnum spider setup.
One runs .575" lift with stock spider setup and stock magnum rockers.
The other runs .565" lift with the magnum spider and 273 adjustable rockers on edelbrock LA heads on a magnum block.
The 565 lift cam was .380" lobe lift. If I remember correctly, there was enough room for .400+ lobe lift.
The size of cam's base circle will make a difference too.
I hope this helps.
