If I go with a
 

4 inch rc suspension lift and either 37 or 38 inch tires, will I have to trim or replace my fenders or can I leave them as they are? Your feedback is mucho appreciato'd

You might get a little rubbing at full flex, but you should be fine. I'm guessing the c182 in your name is referring to the aircraft??? I fly 172's :cool:

Unless you run a truck load of bump stops, I'm pretty sure you'll have to trim (if going off road). Running 2.5" RC lift and 35's, and I had to trim. 1.5" taller lift and 2"-3" taller tires... you get the point. Also, it a lot depends on the width of the tire and backspace. Wider tires and less backspace contribute to rubbing on the fenders under flex. I got 12.5" wide tires and 4.5" backspace.

I just bought rc3.5" flex and planning on going with 37s and flat fenders. My friend has 2.5" with 35s and just cut a little bit of the pinch seam. Am i going to have to cut anything else?

i only have 35s , but did not have to cut anything if i wen to 37s i would have to cut alot...

Do you have the factory bumper? Might hit it if you do.

I have 35's and a 2.5" RK lift and was hitting the front bumper + air dam and fenders. Just chopped the bumper and removed the air dam this weekend. Fenders are next.

Also will probably need to trim the pinch seam if that hasn't already been done.

also if you have rubicon rock rails you will need to cut them as well.

I already cut bumper and put stubby caps on. No rocker rails yet...

Do I still need to trim the fenders even if I don't do too serious rock crawling??

Probably not. You could get the wheels and try it out. Even if it rubs a bit, they're not going to fall off. The fenders flex. Then if it rubs too much, trim.