How can you distinguish the Olds 350 from what?
If you mean from other V8 engines - look for the oil fill tube on the right front of the block, the valve covers will be a rounded trapezoid with 10 bolts, the dip stick is on the left, the intake manifold will also cover the lifter valley (Pontiac and Cadillac intake is raised with a tin valley cover), the distributor will be on the rear - Buick (1967 and later), Cadillac, Chrysler (big blocks) and Ford are on the front of the block but will not go through the intake manifold like a Chevy.
Keep in mind that all Olds V8 engines built after 1964 (330cid), 1965 (400 and 425) 1968 (350 and 455) 1976 (260 and 403) 1980 (307) share the same basic design and have the same appearance. The 400, 425 and 455 are taller and wider than the 260, 307, 330, 350 and 403. Get the engine casting number off the engine block. It will be to the left of the oil fill tube just to the rear of the timing chain cover.
As for ROCKET - all Oldsmobile (built) V8 engines are ROCKET engines. Rocket was a Madison Av. slogan used in 1949 and it stuck. So if you're looking for a difference between an Olds 350 and an Olds Rocket 350 - there isn't one.
Some names given to Olds engines over the years:
215CID - Rockette, Jetfire, Turbo-Rockette
303, 324, 260, 307, 350, 403 - Rocket
371 - Golden Rocket
394 - Sky Rocket
330 - Jetfire
400 - 442
425, 455 - Super Rocket
I may have missed one or gotten one or two wrong but you get the idea.
If you can be more specific - please ask.
1966 Ninety Eight Convertible - 425 Tri-Carb, Factory Dual Exh, Switch-Pitch THM400, 3.54 Posi.
1966 Catalina Wagon - 421 Tri-Power, M21, 4.11 Saf-T-Trac, 8 Bolt Wheels
1989 IROC-Z - 5.7TPI