biggest wheel and tire and not tub firewall and not move clutch

Hey guys im new here... Whats the biggest wheel and tire i can go with and not have to tub the firewall and preferably not mess with the clutch??  Its a 99 taco  not gunna be bodied and I would like to keep my ac.  so do i have to modify it...   the only thing that I'll do on the frame is prolly z it an inch or so....  Thanks guys so much!!

i was also able to clear on 17's, but 19's I had to move my clutch. I also have a 4" BD....so its all going to be in relation to your bodydrop size, wheel size, tire size, and suspention components. I was all stock front end parts. -=Brad

hey zip tyed what size tire are u running? and did u z your frame to layfull frame? thanks guys

My 04 was laying frame on 19s on 225/35/19 with out tubbing the firewall. they were right up against the cluth but still layed and it was also z'd 3/4