Chevy carte motor casting number 10066036 how much power it puting out?

There's no way to determine the horsepower output of a Chevy small-block engine solely from the casting number 10066036. That number identifies the block itself, not the specific internal components (crankshaft, camshaft, carburetor, heads, etc.) which drastically affect horsepower. Engines with that block casting could range from very low horsepower to very high horsepower depending on how they were built and modified.