Have run standard shim and spring setup on 263 8.35mm lift cams for over 5+ years. Never an issue. I do have a box of Toda vavle springs but never got around to putting them in.

When putting cams in, a de-dagging of the head is a good start if not porting the head. Cam gears also great idea to dial them in.

A re-shim is MANDATORY, but is piss easy if you've got a spare head (or just spare shims). Just follow the factory book on how to do.

The true technical answer is that the ramp rate of the cam is critical in determining if the cam will spit a shim. Lift will cause spring binding, float and fatigue. The lay-mans answer is that if you buy from reputable brand, under 8.5mm lift, you won't have any major issues.