locating large round parts on CMM and clocking them

Well I guess first silly question would be what machine do you have? 
I have a DEA you can park multiple cars inside, with an overhead crane, and parts larger than the average car. We have a steel large steel fab table with a bunch of modular tooling blocks. We just set up our table and then gently move the part into position against the stop blocks. 

In your case it sounds like you don't have that option. Run a 4x4 across your machine against the columns and butt the part up to that? Better yet a 4x4 with some blocks sticking out of it to catch the part in a V-shape to center it and give your something to rotate against, spin her into place and set it down. If tis too heavy to rotate, then get a ratchet strap and a piece of pipe and make a strap wrench. Mark on your table with a sharpie some reference marks you can use to clock the part. 

There are ways. 

Well I guess first silly question would be what machine do you have? 
I have a DEA you can park multiple cars inside, with an overhead crane, and parts larger than the average car. We have a steel large steel fab table with a bunch of modular tooling blocks. We just set up our table and then gently move the part into position against the stop blocks. 

In your case it sounds like you don't have that option. Run a 4x4 across your machine against the columns and butt the part up to that? Better yet a 4x4 with some blocks sticking out of it to catch the part in a V-shape to center it and give your something to rotate against, spin her into place and set it down. If tis too heavy to rotate, then get a ratchet strap and a piece of pipe and make a strap wrench. Mark on your table with a sharpie some reference marks you can use to clock the part. 

There are ways. 

big vees with roller bearings