318 instead of 273

I have a 1966 Valiant that has a 318. The guy that rebuit the motor put solid lifters in it. I'm hoping he put a solid lifer cam in it as well. I'm having a hard time keeping the valves adjusted. The current set-up is stock 318 push rod with the cup type end and ball type adjusters. The current adjusters are interference fit and I'm thinking that they are backing off. I bought some new adjusters from summit that have a jam nut but have not installed them. I'm I wasting my time? Is this ball/cup set-up for hydraulic lifters only?