I don't know either (yeah, no much help there) but I would pull it out anyway for the following reasons:
1. More room to work.
2. Less chance of damaging it.
3. The system is drained anyway.
4. Opportunity for a really good flushing out, possibly even having a radiator shop do a thorough cleaning.
5. Good opportunity to replace the hoses and inspect the rest of the area for rust, oil leaks, general wear & tear.
Just my 2 cents worth!