Stacking x440 48p 10g switch to x440 24p 10g switch using SFP+ ports

yes it should remove the config.
As we are enabling stacking for the first time we need to reconfigure it.

Oh my, this is going to completely disrupt our 24x7 production then. Is there any other way?If you must have a stack, there will be some downtime to make sure everything comes up as it should. A few reboots as well.
How complicated is your configuration (VLANs, etc.)? It might end up being relatively easy to convert the config into a stacking config to help minimize downtime.

You could also create a 2x10G port group and let one switch handle all of the IP routing, while the other is all switched at layer 2. That's probably the quickest way to get up and running while you find time to schedule a proper maintenance window to set up the stack.

Our current config on the switch has 7 different Vlans configured on it. Can I connect the 24p switch to the 48 port switch via SFP+ without having to stack them?

Stacking is nice because it allows you to have a method for managing both switches together as one logical unit. If you're okay with managing them separately, you'll be able to connect the two switches without issue. You'll need to tag your VLANs for the uplink port(s) on both switches so that you can break them out on the new switch. I'd recommend creating a 20G load sharing group between the switches to reduce bandwidth bottlenecks.
If you're unfamiliar with these processes, it might be a good idea to open a ticket with GTAC so that someone can take a look at your specific config and help guide you along. They can also help convert your existing config to a "slot:port" arrangement for stacking.

What cable did you use? I need to pick up a cable now to connect a X460-G2 VIM-2x to a X440 using the SFP+ ports. But I"m not sure which cable I need.