Will 35's fit?

[82oldskid]

I've been looking for tires lately for my 86 3/4 ton.  currently i'm running 305 70 16's, but i've been wanting to go up to 35's.  problem is, i dont know if they will fit.  i know the truck is lifted, but not sure how much, as I did not put it on.  i have noticed rub marks on the mudflads with the 305's, but yet i never hear any rubbing noises, no matter how hard i cut the wheel.  either way, the fact that i do see those marks makes me leery that the 35's will rub.  anyone know what i can do to figure out fitment?  also, how can i find out how much my truck was lifted?  thanks all!

[Irish_Alley]

turn your wheels to the limit and see how much room you have

[bake74]

     The stock springs on these trucks were inverted,(meaning they looked like they were bent backwards when on the truck).  If your springs look like they have a positive arch, then it is more than likely lifted.  Most were lifted with a 4" lift kit.
     The only way to tell for sure would be to measure the spring (while on the truck) from spring eye to spring eye, make a straight line across, then from that line straight down to where it mounts and compare with someone who has a 4" or 6" lift on.  It is possible it might be a 2" lift, but I doubt it. 
     Are you sure you do not have any kind of body lift kit on ?

[slammed79]

Your 305/70-R16's are 32.8" tall brand new, call it 33's, If those tires are will in good shape tread wise, I'd leave it alone for now. 35's are awesome but expensive and won't help in the fuel department.

[82oldskid]

hey all, thanks to your answers so far.  in reply...

Irish_Alley:  I'll give that a try, and see what I got.

bake74:  I do know 100% that this truck has a suspension lift, as it has the lowered brakets for the brake cables/hoses and pitman arm.  also has blocks on the rear axle, just guessing as ive never measured them, wanna say 2-3 inch.  i can get an accurate measurement if you want.  and no, definitely no body lift.

slammed79:  my tires are done, they're getting real smooth in the centers, so thats why i'm in the market.  from what i've been pricing, its seeming like the price of 35's aint much more than 33's, so i figured if i'm gonna spend that much, why not go bigger?  as for fuel issues, it doesnt bother me...  my thing is, a truck is meant for work, not fuel mileage.

If it helps, I'll see if i can post some pics of the truck and the suspension tommarow, if i get time.

thanks again to all, any other thoughts?

[bake74]

     I bet if you measured the rear blocks you would find them to be 4".  With that being said, 33" is the size of a 4" lift (recommended) so as not to hit tires.  If you do not take it off the pavement you could run 35" tires with slight rub when fully turned and say entering a parking lot with a dip in the road.
     If you take it off the pavement at all I would stick with 33" tires.

[thirsty]

The width of your rims and the offset will be a factor in this too. Chances are that if you have 10" wheels with only a 4" lift then new 35" tires will modify your fenders for you. You would have to pound your truck pretty hard to make 33" tires on 10" wheels rub.
Also fatigued springs will come into play as well as soft ride lifts. They will let the axle travel more. I prefer a stiffer spring for these trucks unlike most people. I think the only way to tell for sure is to bolt on a set and see. Do what Irish suggested with your old tires and then do it again with the new ones. Don't forget that if your tires are done for like you said, they are going to be a smaller diameter.