There has been several occasions that a properly tuned VCT motor has made more power than one with a VCT delete and adjustable gears.
But yes, you cannot run standard zetec cams on a VCT motor. The journals are not the same size.
04 ZX3 RIP [Best Non-SVT FITF12][3/13 ROTM][7/14 ROTM][2014 ROTY][Best Engineered FF14]
01 SE V8 Estate [Organizers Choice FF15][2nd Place MK1 Class FF16]
02 SE SVT Wannabe
02 SVT Future Project