Think I found the right prop but need a little more RPMs. Currently running 5900 and looking to get up to 6300. Rther than buying more props, will labbing my current one give me a bump up in rpms?

Potentially yes it will increase your RPM somewhat, but I would recommend measuring the blade thickness, prior to doing so.

There are many options to increasing the rpm's with Mercury Racing #6 propellers.

In 1999 we decided to stop offering Box Stock versions of the #6 family of propellers (3blades went away too). In otherwords, you could only buy Lab Finished versions. There were a number of reasons for that decision. Standard Labbing fromStock to Labbed was about 300 rpm's.

If the propellers are post that time frame, they will need other adjustments to gain the desired rpm. This is definately a viable option. These ways would need to be discussed to determine what is best for your set up.