Full Synthetic or Semi-Synthetic Blend?

[TexasCobaltGuy]

After the top end rebuild I put Full Synthetic in it but now I’m several hours in and thinking a good insurance plan would be to change the oil again to make sure I clean out any containment’s that’s might have got in the engine while I was doing the heads

So my son picked up oil at the dealership and they gave him semi-Synthetic but on the last oil change I put full synthetic in it. So question. Any preference on one over the other? Any concerns with switching? I didn’t change the oil before this past time so it very well could have been semi-synthetic that was in it from the deanship?

[akorcovelos]

For engines circa 1990s OE would have been semi-syn, not full syn. That old story about not being able to switch from syn back to blended or even straight bone juice is a wives tail. I've switched back and fourth many times on my vehicles without issue. What you will run into on these older engines is they can start to leak if you run full syn as the tolerances for oil seals weren't as tight back then. Just my personal experience on that.

[TexasCobaltGuy]

Perfect thank you for the advice!