How to tell the difference ( H.O. or not)

This is not a roller there lifters are much taller. This is standard flat hyd.

OK, this one has the XXX but it is a hyd lifter engine. I believe its just a standard carburated 84/85 302.

Depending on the block numbers it could be a later roller capable truck engine too.

This was pulled from a 84 RS Capri . It was a complete engine with a little over 54k on it. Came with its original dual snorkle breather and Ford dual plane aluminum intake and shorties , and original Holley motorcraft carb. . When we spec out the lift its on the money. I gave $50 for it complete.