As long as you have the right kind of controller (SCSI? IDE?) and cables to plug it in, go ahead and try. No PC that I know of just formats a hard drive because you connected it... you have to tell it to do so.

Linux should recognise the Sun label on the disk and allow you to mount and read them as long as your kernel has the required modules and utilities to support mounting UFS filesystems (I'm guessing that's what you used on your SPARC).