I am not sure, but I think that I remember hearing 33". Yea, I think that is about right, depending on the brand. Sorry, don't know of any sites. Although I do know that black diamond and pro-comp make kits, you can look them up.
Russ

 

I assume you say you are going to use stock YJ springs. If so, 33s are about it if they are in good shape.

Brad (from the 4 Wheeling center of the universe, 4 corners USA)

 

Correct answer, but those folks don't make spring-over kits, they make coil conversion kits.

 

94 YJ w/ SOA and loving in for 3 years now. I run 31's and have NO problem. So much NO problem that I think the people who have
answered you with 33's may well be right! I have NO rubs or anything! (BTW - you will have some bump steer and don't believe anybody
who says otherwise! But you can live with it I am sure. The articulation is a quantum leap! Go for it but you need to undersand this
caveat of engineering: all decisions are a compromise. This will include the engineering decisions you wil make and execute soon.
THE ENGINEERING DECISIONS THAT RESULTED IN THE VEHICLE YOU HAVE NOW ARE A COMPROMISE THAT YOU HAVE
FOUND LACKING OR AT LEAST DISAGREE WITH! That is why you are modifying your Jeep! Understand this basic premise and you
will be perhaps more tolerant of the compromises you create.
(too wordy!)
JMTCW
sln

 

33s will fit easily. You'll be able to do 35s with 1" adda leafs and some fender trimming, 1throw a 1" body lift on top of that and you coul go for some 36x12.5 Swamper Radials.

IMHO stock YJ springs alone are too soft for a SOA. I'd suggest you take a good look at the Rubicon Express and Rancho full length adda leafs. Both are about the same. They stiffen your spring packs just enough to help the handling and take a bit of the pucker factor out of steep sidehills, but they don't seem to hurt articulation. Another option is to get a second complete set of YJ springs, cut the eyes off the main leafs on the sconde set and add in those leafs as ada leafs. I did this, and I still needed to put in the one more leaf from the second set to really make it right, but I have a heavy Jeep.

There's a ton of info on this in the Jeep-Tech section of Off-Road.Com

 

The setup I have right now is a suspension lift(add a leaf I believe-I bought the Jeep this way and it is a real stiff ride)which is in the area of 2.5", a 2" body lift(this was done for fitting purposes of the CJ clip on my YJ). I am running 33x10.5 BFG AT KO.
The stiff ride I don't really mind, I mean it's a Jeep.
I wouldn't mind running 35" tires in the future.
Now with a switch to stock YJ springs with SOA and the 2" body lift does it give me enough room to run the 35's?
If I stick with my add a leaf springs, 2" body lift and SOA am I looking to some real problems in the handling department?
I drive on the conservative side both on road and off road. I prefer to error on the side of caution.

Cutch 88YJ

 

I'd think 35s would fit with your 2.5" lift and a SOA. You'd probably be alright with the stock packs and 2" body lift too, but I like the first idea better.The stock springs are just too soft when you go SOA, and they tend to sag out quickly becuase all the extra articulation fatigues them. I don't think it would be more than a few months before you started to think about putting those adda leafs back in.