recommendations for oil AFTER breakin

anything you want. as long as its no less than 1200ppm phosphorous/zinc content life should be hunky dory. if it is less, add some lucas zinc additive. good thing to remember, lucas claims their 16oz bottle of break in additive mixed with 5qts of API SN oil will get you approx. 5200 ppm zinc/phos. thats entirely overkill after initial break in. with that being said, almost all API SN oils are closer to the 600ppm and SM is closer to 800ppm. most API CJ-4 diesel spec oils are 900-1200 on a good day. anyway, lets say the SN oil (in any quantity really, the approx 600ppm doesnt change with volume) is taken from the equation, that leaves about 4600 ppm in lucas' 16 oz bottle. 4600/16= 287.5. so with the approx 600ppm base, youre shooting for 600-800ppm more. 800/287.5= 2.78. so youd need 2 3/4ish oz. or, 600/287.5= 2.08. so about 2oz. of break in additive. not the full 16 like lucas claims "for ultimate protection in every oil change" too much zinc/phos in a DD is bad news too. racing, sure, but a daily....ehhh not so much. lookup camshaft spalling. thats what happens with too much zinc and phos. so be smart about it. and if im wrong someone please chime in. ive done this with a built to the nuts 327 chev and a moderately built AMC 401 and havent had a problem yet.