Om my 454 where should the roller rocker be on the valve stem to be correct.Where should it ride with valve closed and open.any info would be great,thanks

The wear should be in the middle of the valve stem. At rest it will be just towards the intake manifold side of the valve stem and at full lift will be just past center towards the exhaust manifold side.

Take a black felt tip marker and cover the top of the valve stem. Assemble the pushrod, rocker arm and adjust to specs. Rotate the engine a couple of full revolutions and then remove the rocker arm and see where the wear mark is. If it's centered on the stem you're good to go. If it's more towards the intake manifold you need a longer pushrod and if it's towards the exhaust manifold side of the stem you need a shorter pushrod. An adjustable pushrod sure makes this easier if you need a non-stock length.

Jody

thanks for the post i will try that. If i need a longer one where do i get one from,