split the quart between the 4 cyls, and save some for the gas tank and the oil.
a few ounces in each cyl is plenty.
adding it to the gas will help upper cuyl lube.
adding it to the oil prior to change.. but after running, will help witht he drain out.
on a new to me machine.. I have added 1/4 quart to a gallon of gas for testing. 1 quart in crankcase. and another quart split betweent he cyls.
atf is cheap and decent stuff.