Codes p0301 and p0335 even after replacing those specific parts. What next??

Hello, those part replacements are OK guesses related to the diagnostic trouble codes that were set -- except probably not the crankshaft position sensor. However, true testing isolates the concern to ignition components, fuel delivery components or even a base engine compression or timing issue. Until needed testing is performed, it's impossible to know if you have resolved the problem or not. Are you still getting a check engine light? Is it flashing? Is there any engine performance issue remaining? As far as the coolant leak, have you had the system pressure tested for coolant leaks?