TxGoat wrote:
Putting new lifters on a used cam may not be a good idea. Mixing the positions of used lifters on the cam may not be a good idea. If you continue to have issues, I suggest removing all of them, keeping them in order, and take them apart and clean and inspect them. Do not mix parts from one lifter to another, ever! Hydraulic lifters have a limited range of function, and need to operate within that range, which typically requires an initial adjustment. Factory procedures and specs would need to be followed. The lifter needs to be able to expand when the engine is cold to maintain proper valve clearance, and collapse slightly as the engine warms up to maintain proper valve clearance. A stuck, bottomed, or topped out lifter plunger cannot do this.

I'd want to run the engine several hundred miles at moderate speeds to allow the fresh oil and Marvel oil a chance to clean up the lifters, rings, etc. Any cleaning effect will occur when the engine is warmed up and running. I'd keep the engine speed down, with road speeds in the 45-50 MPH range or less. Longer runs are better than shorter runs. The idea is to get the engine warmed up and running, and the hot oil circulating. Runs lasting an hour or more are best. If you have an oil filter, I'd start with a clean element. Correct any missing or other tune up issues. You want the engine running on all cylinders.