Hockeypickles23

So we just picked up a nova ss with a zz4. It has a cam, intake, and carb. The builder's notes and previous owner's notes said that oil changes were done with 20w-50. I was wondering if I could continue the trend or put the recommended 10w-30 in? It has between 55-65 psi when warm and near 70 when cold.

EDIT: this morning when started up it was at 55 psi. After idling for 15 mins it dropped to 40 and was still dropping. I am going to continue to use the 20w-50 as it lubricates well. Only downside is that it takes forever to warm up.

2ND EDIT: Switched over to a synthetic 10w-30 and starts at 55-60 psi and at idle, warm, is around 25-30psi which is perfect for a ZZ4

cv67

10-30 is ideal imo
thinner, flows quicker and still has a good cushion for bearings
only reason to go thicker is if the engine was built real loose which those arent

99Silverbullet

20w-50 with zinc additive is mostly used for engine break-ins..ive got it in my freshly built 396