What happends if i dont run synthetic in my engine? Will i get lots of clunks because of the lt1?

 

Run synthetic. It is all around better. I run Mobil 1 5w30 or Castrol 0w30. Royal Purple Race41 is also a good formula. Redline and amsiol are also GREAT oils.

Synthetic is what these cars were designed for.

 

You will not notice any difference when using regular "dino" based oil instead of synthetics - nothing is going to "clunk". You will have to change your oil more frequently, particularly if you experience extended periods of high temperature engine operation. But otherwise, dino oil meets all of the manufacturer's requirements.

Synthetic offers the advantage of longer life, better resistance to breaking down at high operating temperatures, more uniform viscosity over wide changes in operating temperature, and generally reduced engine wear.

 

I would argue the recommendation of M1 5w30 specifically, just because Mobil got marketting rights and got GM to use it as the synthetic supplier for the Vette does not make it "best", you would be better off with 10w30 if using M1. The Vette did need synthetic but Mobil being the choice had nothing to do with quality or anything(not that M1 is bad) and everything to do with them being the biggest manufacturer and marketing. The 5w30 is CAFE at work, analysis proves the LT1 wants something a tad thicker than M1s 5w30.