How do I know if these guitar tuner machineheads will fit my guitar?

I changed the heads on my electric when I refurbed it several years back. It was literally just take out the old ones drop in the new ones for me. But they weren’t machineheads like this, and though I didn’t have to drill new holes because my old ones matched, it wouldn’t have bothered me if I did because I repainted it.

Honestly I would suggest calling the manufacturer and asking. That’s probably your best bet.

side note: I personally don’t care if they’re fancy aftermarket machineheads. I’ve heard they stay tuned a bit better, but I’ve never had issues with my standard ones on my acoustic. Not worth the large investment to me.

I agree with @tedd, check with the manufacturer.

I changed tuners on my old Eko 12-string about 15 years ago. She’s about a 1957 model, and the screw gears on the tuners were either worn or wearing. I went to a local repairman that I’ve known since the 1970’s and he hooked me up with some that looked original.