I have to pull the 340 out of my demon to replace the clutch and rear main seal (and to repaint block) and was going to go with a different cam while it was out. Is there a manufacturer that makes a hydraulic roller cam and lifters that are a drop-in application? I don't want to take the engine apart to modify it for a roller cam and will stick to a hydraulic flat tappet if necessary. The engine is an early 70's 340 block. I would really like to know what's out there though and what works from your experiences. Any help would be greatly appreciated!

When I die I want to go like my Grandfather did, quietly in his sleep. Not screaming like the passengers in his car.