Schmidty

Hello, I am new to the Forum so here goes nothing.. I have been working on restoring a 1975 Yamaha TX 500 for quite sometime now. I had it fully operational until i noticed I had a leaky head gasket. So, with much contimplation I purchased all new head gaskets and pulled the Motor and opened her up. With buckets of degreaser and a Clymer manual i went to work. I pulled the head off and the cylinder block replaced the gaskets and through it all together. Now, I read in my clymer manual that to install the cam chain you need to set the governor plate to "V" and match the punch marks on the cams to the mark on the head. This seemed very suspicious to me because i thought cam timing started with setting the #1 piston to TDC (At least thats what a couple of Forums have said). SO, my question is how do i set the cam timing correctly. Do I set it to "TDC" or to the "V" mark?