Check the number stamped behind the dizzy. Make sure the block is a "car" block. Truck engines were not drilled for hydraulic lifters.If you have a block that is drilled for them, you might need to "bleed" them. Pull each one out, put into a can with oil over the top of the lifter. Push a push rod into the lifter until it won't compress any more. You will feel it get hard. Put it back and pull the next one. Do this until they are all done. Then set the valve lash just loose and start it up. They will click a bit, don't worry. After it is all warmed up set the valves again and you should be fine. There is a good tech tip on here about adjusting valves.
