Yes I've already bought a torque wrench today

I've got another question. If I put the head back on and want to put on the cam chain tensioner, can I just use a screwdriver to hold the tensioner closed until i put the cams and cam chain in and then pull out the screwdriver to open the tensioner? Because that would save me $50 Also how do you tell if the cam chain tensioner is working properly? It sprung out when I was playing with it but it wasn't wicked fast like I thought it was gonna.