I'm pulling my engine this weekend to replace rings, mains, rod bearings and add vortec heads along with a few other things. Is there a general rule on breaking this engine in. I've heard run it for 500 miles on dino oil and a good filter then switch to synthetic oil. I've always kept the oil changed with an ac delco filter and Mobil 1. Anybody got any better ideas?

 

run it with 30w dino juice, start it and set the timing and idle. then run it around 1500 for 15 to 30 miutes at varying speeds and change the oil and filter and refill with 30w again. run it on the street and load the engine from 1000 up to around 4000 going through several heating and cooling cycles. at the oil change interval run what ever oil you like. i bet if you did a search you might find something on this.

 

Here's what GM recommends with their new crate engines:

Breakin.pdf