rangerfredbob
Veteran Member
The not running synthetic oil til a certain hours is about piston ring break in... dealing with that at work now with an LS based 454 for boats, the ring manufacturer is recommending dino oil for break in... Same with the not towing on first however long but that's not near as much of an issue as it used to be... We sell engines at work for a living and GM themselves do not recommend a breakin period, they say just run it which is the subject of many phone calls...