I have a 91 4runner, doing a SAS with 5" leaves. I found a wicked deal on some 37" tires, but I'm wondering if they will just rub like crazy when I start to flex out? I don't think the front will have much issue, but it's the back i'm more concerned about.

 

Sounds like you are planning to swap the rear end to leaves... is that right?

My bet is you'll be close running 5" springs with 37's. Will depend on wear you set your bumpstops and how good you are at judging fore/aft axle position when you setup your springs.

I am in a similar boat, but am more concerned with front clearances if stuffing under full turn.

It's also going to depend a lot on the brand and width or 37's you are looking to get. Some 37" tires are pretty small... and some are a true 37" diameter. A wider tire is going to make clearance issues a lot worse.

 

Realistically you will need to probably tub the firewall and trim the fenders if you do not want to tear up your tires and or sheet metal.

 

I cant touch my front tires on any of the sheet metal.

 

Just set your bump stops to keep the tire from touching the fenders. You should be able to clear them fine.

 

I have 93 4Runner with 37 MTR's on 3 3/8" BS 8" rims

4" marlin springs up front (1 leaf removed)
- Front Hanger in 1" froward Position
- Moved the front axle 1 inch froward from normal position
- Trimmed the stock front bumper
- No issues with the Front

5" Alcans in the back
- Trimmed Front of Fender
- Still some Rubbing on moderate to heavy articulation
- Probably need to move axle back an inch and trim rear of fender also

 

Trim.