What motor oil to use on a rebuilt 351 v8?

For a rebuilt 351 V8, it's generally recommended to use a high-quality synthetic or conventional motor oil with a viscosity of 10W-30 or 5W-30, depending on the climate and operating conditions. It's important to look for oil with a higher zinc content (ZDDP) to protect the flat-tappet camshaft commonly found in older engines. Always consult the engine builder's specifications and follow the manufacturer's recommendations for the best performance and longevity.