Spring Locating Question

Right now I am planning my budget EQ head project. I have been looking over and over at Mopar Actions dirt cheap 360 build and thinking about some of the ideas they used on the heads.

Ehrenberg used circle track springs Comps P/N 26975 springs which had a .920 ID. The EQ supplied heads are equipped with .812 OD locating diameter. E Berg stated "the comp springs are a tad sloppy" with regards to their retainer to spring fit. BUT "thats not a problem since they locate perfectly in the heads spring pocket".

WELL, I have a bunch of magnum retainers. I havent measured them at all and dont know if they are a good part reliability wise or what, so I can only assume that they are identical to the EQ retainers. Is this the case?

Also, how do all you engine gurus feel about using the spring pocket as the only means of locating the valve spring?

FWIW, I plan on using those budget stamped roller rockers (1.6) from summit and also summits stud conversion for the EQ heads. Engine will be a Hyd Roller 318.

Thanks