Upgraded Processor Experiencing Random BSOD Errors

I'm at a loss. I recently tried to upgrade my CPU from an i5-4670K to an i7-4790K on my machine. Previously it ran fine for 10 (!!) years with no issues, just upgrading the GPU and adding RAM as time went on.

Current specs:

OS: Windows 10 Home

Motherboard: ASUS Z87-K

CPU: Intel i7-4790K

GPU: EVGA GTX 1660

RAM: Corsair CMZ8GX3M2A1600C9B Vengeance 16 GB (4X4 GB) PC3-12800 1600mHz DDR3

PSU: Thermaltake 600W

After installing the new CPU I started getting random BSOD errors (kernal mode trap, IRQL not less or equal, machine check exception, among others). At most I've been able to run the machine for an hour, but most of the time I'd get different errors back to back within minutes. I thought it was a driver issue so I updated everything I could, but still nothing. Ended up reinstalling Windows but the errors persisted.

I ran Windows Memory Diagnostic Tool and Intel Processor Diagnostic Tool and both came back clean. Double checked the RAM with Memtest86 and it passed as well until I ran it again in parallel mode. Then it gave a UEFI error:

"Could not start CPU 4"

Is the CPU damaged in some way? The fact that everything has been working fine for so long kinda tells me it is.