There are, but pricy at about $400? I just bought one used, made by Bullet, for half that. EDIT: for a Magnum, but will go into an LA roller equipped motor. I understand they do have the right cores for your project, though.
I read about guys wanting to run a stock mechanical fuel pump in a 5.9 magnum, and the factory rollercam for the later LA360 fills the bill for that because it has the eccentric they have to have to run the pump. Just tossing that info out there in case you want to run a Magnum, with good heads.