It's not as week as the F or 2F in my 87 FJ60!
The Pin 7 mod is this: when done it allows you to have manual control only of locking the center differential when shifting into Low Range. You can still do the PIN 7, it won't hurt anything, but remember that your truck will not automatically lock the c-diff when you shift in low, you have to do it manually from now on. Here in Iowa you will not see much benefit from this 'mod'. If you were doing a lot of wheeling on high traction surfaces like sandstone or something similar I'd recommend it. Also will help if you do some towing...
If you will only be buying 4 tires, you need to stick with the 31" tires. Mounting a 31" tire (after you get a flat) on a otherwise 33" equiped rig will cause issues.
The Pin 7 mod is this: when done it allows you to have manual control only of locking the center differential when shifting into Low Range. You can still do the PIN 7, it won't hurt anything, but remember that your truck will not automatically lock the c-diff when you shift in low, you have to do it manually from now on. Here in Iowa you will not see much benefit from this 'mod'. If you were doing a lot of wheeling on high traction surfaces like sandstone or something similar I'd recommend it. Also will help if you do some towing...
If you will only be buying 4 tires, you need to stick with the 31" tires. Mounting a 31" tire (after you get a flat) on a otherwise 33" equiped rig will cause issues.