I had 305/70/17 with -38 offset on my 2019 4runner (now they are going on my 2021 4runner).

I just finished putting 315/70/17 on 2022 gx460 (same concept as on 4runner).

The truth it there is no easy answer to will it fit. That is why you will get 100 different opinions. Each tire manufacturer is slightly different in advertised sizes. Each vehicle (believe it or not) is slightly different. Your upper control arms may be different then the guy giving you advise (less/more camber).

The short answer to your question is if you don’t want to trim; stay with 33s. If you are willing to trim; you can go up to 35s.

Trimming will be different for every vehicle so your only option is to take the coils and shocks off, jack up the tire to max, adjust bump stops. Turn side to side and start trimming and banging (may be required for some sheet metal).

It took about 8 hours of trimming for 34s and about 20 hours for 35s. A lot of taking tire on and off!

The other things to consider is steering component wear / breakage. I’d be OK with 33s and any weight on car. With 34s I’d be ok with a light bumper and winch and not much loaded. With 35s…. Your going to start breaking tie rods if you have too much weight/abuse.

Last to consider is gears…. That’s on you and easy to research. Not needed but nice. If you’re on 35s…. Don’t go 4.88 though if you wheel. You’ll break them.