My P38 had an engine swap with another GEMs 4.0l. I have done 2 full oil changes with filter swap and refilled with 6.5qts. The oil reading is probably 2.5 inches or more higher than the "full" line. The length of the dipstick is 30 inches.

I don't understand if I am referencing the wrong oil volume for a 4.0l or if somehow I have the wrong dipstick after the engine swap.

As a side note I have an odd rumble/knock upon startup so I concerned about an overfill.

Any ideas?