Help with crossover capacitors


I am re-capping some Altec Lansing 890C Bolero speakers.  They have 6uf/50volt and 3uf/25 volt caps.  What will change if I use 5.6uf and 3.2 caps?  I can't find the exact 6uf and 3uf values.  Should I go a little bit higher on those values or lower?  Any suggestions?  I'm looking at Dayton, Mundorf or Jantzen caps but I'm open to suggestions.

dannybad
Just one caution: how hard do you drive your speakers? The 300R, 12 watt resistor may get hot when used hard, in place of a 15 watt. Have you considered doubling up in parallel? I would be sure to meet or exceed all voltage and power specs, and match values of resistance or capacitance as closely as possible.

Rather than brand name, consider technology when buying caps. Film and foil is notably better than any metallized product. I like tin foil and styrene film, especially from MIT multi cap - pricey, but worth it in spades. Mills is good unless you have deep pockets.
These speakers are rated at 50 watts at 8ohms.  I'm going to buy the Yamaha s-501 which is 85 watts per channel at 8 ohms.  I will turn them up and listen to them loud sometimes, but "loud" is a relative concept.  How exactly would I double up in parallel?  Would I just use 2 of the same resistor?  
Those are modest figures - I think you should be fine. I would not bother. But if you want to do so, the rule is twice the resistance for two resistors in parallel.
Great.  I think it will be fine as I really don't push them too much. Thanks for commenting.  Everyone on this thread has been so helpful.