Howard:
Welcome to the site! Verify that the rockers you have are intended to be used with these heads. If so : It sounds like rockers you have are non- adjustable (like most OEM Ford), they utilize "sleds" that align the rockers and allow the rockers a point to to pivot on (instead of roller bearings) when the sleds are tightened down to the heads. All things considered there is usually enough allowable adjustment in the lifters to arrive at "0" lash once they are tightened down and
oil pressure is initially achieved. This is assuming that the valve to piston clearance has been verified so they will not hit each other, pushrods are the correct length and neither the heads or the block surfaces have had excess amounts of material removed. Tighten them down as you cycle through the firing order and you should be ok. Initially there will probably be some "clicking" in the valvetrain when it is first started untill the lifters presurize.
Good luck
Rick