Good point. Doing the obvious things like the lip below the seats and removing any casting flash/irregularities should be the extent of it unless you have experience and/or a lot of time and a flow bench- along w/enough heads to find out what is helping and what is hurting. After all, if you remove too much or from the wrong place, the head is now scrap; you cannot add the metal back and welding is in no way cost effective on these commonly available heads.
FWIW, there have been good builds using the L30 305 Vortec heads on the small bore SBC engines. One member here has them on a 283 and likes them just fine. Takes a Vortec intake, self aligning rockers, centerbolt valve covers, and a spring and retainer change.
Some info and photos of the L30 5.0L Vortec head can be seen at NastyZ28.com Vortec Cylinder Heads: The Definitive Guide
, post 478.