Looking for Boveda pack recommendations

Hi, I have a couple of wooden sets that I have stored in some wood boxes I refurbished from goodwill finds and was looking to buy some boveda packs to place in them with the pieces to help prevent any cracks. Does anyone have a suggestions to which humidity level I should go for and how many grams? I was looking at the 8 gram pack for the 58rh, but I keep getting conflicting statements. Anyone with first hand knowledge would be greatly appreciated.
These are the boxes if anyone is interested. The first two images are the same box (an old silverware box, capable of holding two sets, one in the top and the other in the drawer), and the second set of two are the same box, just a nice old box which holds one 3.5 inch set if stacked, which I did...
Anyway, thanks for any help and please excuse my bad camera phone pictures.

This is likely to be a contested topic.  My background is in chemical engineering at which I make my living.  I also have played the violin for 30 years.  I've seen these used for cigars humidors and instruments, but not so much with chess pieces.

I'm not sure the practice of it would be helpful to the long time preventing of cracking -say decades-(It's likely to make the problem worse, due to the sudden change of RH).  If you are going to do it, I would suggest you determine the RH using a hygrometer, and use that value for your humidity level.  This would be for long term storing.  The chess pieces will eventually reach the humidity of the wetted material, and stop (This is an ideal and really won't happen).  It's not good to change moisture percents frequently.  IMO.

It's a matter of how well the wood was treated initially, and the density and quality of the wood.  From the wiki article below, a RH of 10-20% seems reasonable for wood core.  Below 20% keeps microorganisms from growing.  Normal RH where I live is around 45%.  Here is an interesting snippet from it:

Reasons for splits and cracks during timber drying and their control

The chief difficulty experienced in the drying of timber is the tendency of its outer layers to dry out more rapidly than the interior ones. If these layers are allowed to dry much below the fibre saturation point while the interior is still saturated, stresses (called drying stresses) are set up because the shrinkage of the outer layers is restricted by the wet interior (Keey et al., 2000). Rupture in the wood tissues occurs, and consequently splits and cracks occur if these stresses across the grain exceed the strength across the grain (fibre to fibre bonding).

The successful control of drying defects in a drying process consists in maintaining a balance between the rate of evaporation of moisture from the surface and the rate of outward movement of moisture from the interior of the wood. The way in which drying can be controlled will now be explained. One of the most successful ways of wood drying or seasoning would be kiln drying, where the wood is placed into a kiln compartment in stacks and dried by steaming, and releasing the steam slowly.

So, if I was to store something for a long period, I would determine RH, and use that value. 

But, I also would say most of the concern is brought about by fear mongering by online people like StauntonMaster who has no end of offhand dumb comments to make about anything he decides is worth mentioning.  No doubt this article and topic will be usurped by him as well.  Good luck on taking care of your chess sets.  I use several coffers and humidors for my pieces as well.  

Ref: https://en.wikipedia.org/wiki/Wood_drying#Moisture_content

Yeah, I was worried about suddenly changing the humidity level as well (thats why im investigating before buying a bunch of packs). Im in Florida in the US and our hummidity is often above 70 percent from what I can gather looking at daily averages (It fluxuates, but the air isalmost always thick and heavy). Im ignorant when it comes to most of these things so ill trust your judgment and probably steer clear of the packs. Thank you for the info.

I used to collect acoustic guitars and humidity was a huge topic on all the forums.....For wood and in general a safe humidity is between 45-55%......A bit above or below is fine...58% is excellent.

I used the Bovedas and they do work,but you need to keep an eye on them,since they dry out over a relatively short time.....Replenishing does not last long.

The perfect humidity solution is a small portable humidifier.

Echoing @magictwanger on this! My experience is with acoustic instruments as well and conventional wisdom will put the RH anywhere between 40-60%. Avoiding big swings is important as well. From personal experience: I had a fairly well made guitar (in the upper half of guitardom) that i stopped playing for about two years. Life, young family, and trying to make a living necessitated putting it away for a time. To my horror, when i reopened the case, the face was cracked from the f-hole all the way to the bottom. A lifetime warranty covered putting a new face on the guitar but the reason was low RH, around 10-15% consistently. I now live in the opposite extreme, high humidity levels consistently around 90%. We keep the house at 50-55%, a perfect environment for the wall hangers.