My opinion is that the Magnum Style set up is WEAK and I would never use it to be totally honest. I went that route before and could never get the sweep on the valve to be correct not to mention Valve Train Stability issues with the Magnum Stlye 'Chevy" Rocker gear. With bigger camshafts and high spring pressures guys have RIPPED the studs right out of the head that hold the Rocker in place. With the Shaft style not so. No need for pushrod guides or girdles etc when using the shaft mount. If and this is only IF I had to use the magnum style rockers I would use these......
http://www.hughesengines.com/Index/...a2VyIEFybXMgJiBBY2Nlc3Nvcmllcw==&partid=25628
or regular magnum style and these with guide plates.....
http://www.hughesengines.com/Index/...a2VyIEFybXMgJiBBY2Nlc3Nvcmllcw==&partid=24154