Hello

Hello.
I am at the end of my rope.I hope that you can help.
I have a rebuilt 460, which I have done myself.I have been working on cars for about 25 years.
The problem is that the engine is making a ticking noise, when it is idling, but when it speeds up, it seems to go away. Frist thought it was a lifter. This problem seems to be on one cylinder. When the engine was rebuilt, the crank was reground.
What I have done is,
Checked the exhaust gasket.
Tried to use different push rod lenghts.
Replaced lifters and cam, as a set.
Different type of motor oil.
Replaced oil pump, with a high volume and checked rod bearing.
Replaced all valve springs.
All this, and the problem is still there.
Thanks for any help.