Otto has the best link to the VCT operation. I do not believe you can buy a kit to fully lock the phasers. I have read somewhere that a guy welded his phasers so they were locked all the time. Seems silly to me as you will lose all the fuel, emissions, and power efficiencies they offer. VCT is a great concept just not executed the best by ford.
2004 F150 FX4 SCAB
VMP Custom Tunes - Corsa Sport Exhaust