Future-proofing is not an exact science in the PC world and with tech updates with GPUs, CPUs and chipsets with what seems like every other week (exaggerating here), it's kinda subjective... If your question is in regards to gaming, you may find that the following 3 items, if still good for you, no worries, but are things to think of:
1- your motherboard/socket (1155) is dead-end; i.e. No new processors/upgrades being made. Your upgrade path with your existing motherboard ends with an upgrade to an i7 3770k (if you can find one) and then utilizing the unlocked capabilities of this CPU, so at least this is a bonus for you. Your current CPU is still viable.
2- GTX 760; not sure if you have 2GB or 4GB version. Even with the 4GB version, the GPU is probably too underpowered in order to utilize the 4GB of VRAM. This may prove to be an issue as games video requirements start to increase and in the event you wish to game at higher resolutions, whether using a monitor or even using NVidia's DSR settings. Your current SLI setup is still viable.
3- mechanical HDD; SSD, mSATA and M.2 are what's pointing to the future of storage due to faster read/write capabilities and offer low heat and small foot-print in your case. Your current HDD is still viable.
In the interim, I'd say you are fine with what you have, until you find that you start to notice your system having issues with keeping up with new(er) titles or whatever your system is being utilized for.