Okay I am going to be buying some pistons and rods. Which would be the best oil to use to break the car in? Last time I used cheap oil and the car was fine had no problems but I read somewhere that there is a certain oil to purchase to break in the block for longevity thanks.

I have heard to use regular and not synthetic to break in your engine. dont know what brands.

I used cheap synthetic and then put mobil 1 ever since. I just want to be more meticulous since I am setting the block to handle 25-30psi

Last I heard, you use straight 30W dino oil. This will facilitate ring break-in. Once you're satisfied with that, switch to your usual stuff.

Factories now get such good cylinder walls on the assembly line, they don't need break-in oil for the rings.

Use the motul 4000 non detergent mineral oil with is designed for breking-in engines.

don't use synthetic your ring will not breakin right ,it does not let your ring seat right ,you want stuff to wear for proper break in

So then go with motul 4000 and I should be good?

yes.

this oil has no deposit forming detergents this is good if your are breaking in new rings ,and also has anti stuff agents to help ease new parts together.

Sounds good to me do I have to purchase this at like a performance shop?