Double trouble

I dont even hear the valves in my 67 /6! Adjust them and the idle will settle down, lots of things will fall into line with the proper valve lash. Kinda like fuel level in a Holley: It should always be addressed before any troubleshooting is started as so much depends on it being correct from the start. You could probably run a gallon of your diluted oil in you r lawn mower..or even the slant, probably the same compression! Is the tube loose or the dipstick itself? Pull the tube and put a thin O-ring on the bottom and send it home, might pick that slack right up, same on the stick itself.