Wheel/Tire/Backspacing Concerns

Well I have a 74 CJ5, 4 inch of lift, with about a one inch body lift. My plan is to run 33's maybe 35's in a 12.50 width on 15x8 rims. Now th rims I was looking at are 4" BS. How will that ride and look stance wise? I have no idea how to gauge it. Also compared to the stock BS how does it stack up? I obviously dont want rub and on the other hand I dont want the wheels to be sticking out like crazy. Im shooting for a modest stance and look and sticking with the stock type flairs. Bigger axels and all that jazz will come down the road. Thanks in advance for you input and Im curious to see what wheel/tire combos you guys are running on your rigs.

 

With your setup (narrow track): 33s max with 10 inch wide wheels. These should stay under stock flares. I have had that setup. Go for some width.
If you have wide track CJ axles: 35s, after market flares.

 

Any idea what backspacing I should look for? Thats whats really stumping me

 

The 10 inch wheel is typically about 3 3/4" backspace.
I think technically backspacing should be measured from wheel mounting surface to bead surface, not to outside lip of wheel because this lip varies per manufacturer, thus 3 3/4".
Stockton wheel in California (someplace) may be able to make you a wheel with any backspacing (within reason).
Get the 4 Wheel Parts "Rock Crawler" if it's not a show vehicle.

 

what are the gains of a 10inch rim comapred to a 8inch? My pops says I should stick with a 8"

 

bead stays on better at lower pressure.

 

I had to replace the rims on my wifes 83 -7. Went with 15x8 4 inch back spacing on 32x11.50 BFG MTs. Thought the stock rims were 15x8 but after getting the new ones realized the old ones were 15x7. I think the stock rims were 3 3/4 back space and the new ones 4". The outside edge of the tire BARELY sticks out of the flares, which has gotten my failed on safety inspection here in Hawaii! This is with the stock wide track axles. I think 4" is the right choice for a Jeep, very close to stock. You can measure backspacing by cutting a piece of wood or whatever so it just lays in the rim where the weights are clamped on and then measuring from the backside of the wheel were the surface is that bolts to the hub (where the lug holes are) up to the stick held at the backside of the wheel.
For me the 15 x8 are perfect for the 32x11.50s I am running. I agree that the 8" rim helps keep the bead seated at low pressure.
For a 12.50 tire that is a hard one, I have seen 8 or 10". Its a hard call. Anything greater than 12.50, like 14.50 or whatever needs 10" or wider.

On my CJ-5 I run 15x5.5 rims with 30x9.50s. That is kind of a narrow tire and I hesitate to go to 31x10.50s due to that.

 

12.50's on a 8" rim are less likely to come unseated at lower presures. On the other hand if you use it on the road at higher speeds the sidewalls flex more and handling is not at crisp. most jeep, ford, dodge, ihc that you find are 31/2" to 4" most I've seen lately are 3 3/4" or 4" backspacing. I've always liked the 3 1/2" they seem to just stick out from underneath the fenders and are less likely to rub on the springs and the inner fenders.

 

Well yea... I think i will go with the 15x8 3-1/2 BS. Thanks for the info guys