Hub bolts are longer on a 2017 vs 2013
 

I recently had to replace my hub on my 2013 BRZ with one I got from a 2017 86. The bolts that mount the hub to the knuckle were longer, a lot longer. I would say around half an inch longer.

I reused my old bolts but now I'm starting to wonder if I should have just used the ones that came with the hub.

Any thoughts?

What '2017 86' hub came from was? Completely stock and you are completely sure on that (not just from words of owner of that restyle 86)? No possible chance with longer aftermarket studs installed?
If completely sure on that, i'd simply check parts catalog for old and new (too lazy to do right now myself though :) ), but i somehow doubt possibility, as without pressing need imho manufacturers would leave things as universal, backwards-forwards compatible, with reused parts bin, as possible, to have slight, but multiplied by big numbers of both older and newer cars, savings on reduced parts inventory, simplified logistics, simplified servicing & it's tooling/procedures, savings of numbers scale and so on ..

Yeah it was from a completely stock 2017 86. Studs were normal length but the bolts that attach it to the knuckle were half an inch longer. Same color and material though.

2013 hub with bolts
28473FL020

2017 version:
28473FL020

Replaces:
28473FG000, 28473SC000

Looks like the same part applies to both cars now. The ONLY Subaru this doesn't fit is the SVX, so the part likely got updated to fit models newer than the BRZ. Some of the heavier ones probably have thicker knuckles, hence the longer bolts.