what oil for newly built engine?

[BlueSmokem5.0]

So I built my short block this summer got about 300-400 miles on the break in oil and 16 passes. When is a good time to run synthetic? I ran Mobil 1 before and the engine looked amazing when I tore it down.

 

[redline5.0]

So I built my short block this summer got about 300-400 miles on the break in oil and 16 passes. When is a good time to run synthetic? I ran Mobil 1 before and the engine looked amazing when I tore it down.

I was told to wait at least a 1000 miles before using a full synthetic from my builder but I also didn't run break in oil. I'm currently running the amsoil dominator 10w30 but not sure what I want to run with the cooler weather coming up here in Kansas.

 

[nosscort]

I ran straight conventional 30 weight for my break in.. After 1000 miles switched to amsoil ss 10w30

 

[SteveG@Lethal]

Joe Gibbs 30 Break In Oil

 

[redline5.0]

I'm worried about the cold weather here in Kansas and running the amsoil dominator 10w30. The only 5w they have is the 5w20 in the dominator stuff.

 

[D98GT]

That Joe Gibbs break-in oil is what my builder suggested but it sure isn't cheap when you factor in 8qts....but then again neither is a built motor haha

 

[RAZRS EDGE]

Joe Gibbs 30 Break In Oil

This. ^