i currrently build up an old rocky mountain altitude and have now bought a race face bottom bracket with 110 length instead of the 107 mm that was installed when it was sold. does that make difference?
1.5mm each side will make little difference. Depending on your RM it may be an advantage to running some chain ring configurations.
Though it may let 'chain suck' and sticking occur more often/or less due to the gap.
Get some pictures up in Reader Bikes about your project.
EDIT, I see it's a '96 Altitude, gump has one of them.
What chainset are you putting on the BB btw.