On my blacktop 20V engine I just installed Kelford cams, 194-Bs with stock valve springs. Max cam lift of 8.9mm (which = 8.65 at the valve supposedly).

I measured the gap between the valve springs at peak lift (as close as I could tell anyways) and there is only 0.020" of clearance! (.508mm).

This is for the exhaust side. I think the problem is stock cams have only 7.6 mm of lift on the exhaust and I am trying to increase it by a mm or more.

And does anyone know the difference between silvertop and blacktop valve springs? Why does toda make springs for both?