Pretty dumb question. And i should probably just run what the engine says. My manual for my 15 sho said to run 5w20. And i always did run 5w20. Yet my new engine says on cap to run 5w30? Should i just run what the new engine says to run, not sure how different the engine is? I have a picture on me now from when it was being put in but i seen it on the cap yesterday. Intake manifold is still old as the new engine was just the longblock.