Wheels, Tires, and Flares, Oh my!
 

So... As she sits waiting for her 6" superlift to arrive I am left wondering what decisions I should make about my wheel situation.

Decided: 31" 10.5 R15 General Grabber AT2s

Mostly Decided: Cragar or ProComp or whatever steel 8x15 soft 8s or equivalent w/ 4" backspace.

Issues: I live in Oregon therefore I must have a fender flare over any exposed tire, so I have been looking into the Pacer Extra Wide Flexy Flares Fender Extensions. These are universal flares and are 4.25 inches wide.

Ok, so the math. old stock wheels had ~6+" backspace on a 7" rim, new wheels would be 8" wide with only 4" inches of backspace. So where old wheels stuck out 1" new would stick out 4".

Question is: is all this logic sound, or should i go with a 5" backspace instead? and not-so wide flares? it is a 4dr so flare options are basically no existent. and she is definitely going to be lift 6" so I was thinking the wider stance would be more stable. Any thoughts?

There will be 4" of wheel from the hub to the outer face whereas there used to be 1" from the hub to the outer face which is a 3" difference. However, the OEM wheel's aren't flush with the fenders (at least the top anyway) so an additional 3" doesn't necessarily mean it will stick out 3" PAST the fender, just 3" past where it is now.

Find a 4" block of wood or something and push it right up against the hub with the wheel off and measure how far it sticks out past the fender. I think the 4.25" flares would work well

Also, there is a guy working to get ZR2 flares on his 4dr, here's his thread: https://blazerforum.com/forum/articl...-4-door-57919/
http://img43.imageshack.us/img43/373...1104131915.jpg

May I ask why you've settled on 31x10.5 with a 6" lift? You should be able to fit 32 or 33

I Have $2200 in the trany, rebuilt with all steel hardparts. Not wanting to burn it up. Think I need to regear it but not sure what is involved. How well do these 4.3s turn that much rubber? I am assuming one would want 10" rims aswell?

Ok, so...

If I do decide to go with 33" am I going to NEED wider wheels or is it just recommended?

And what about the tire width itself? 33x11.5-12.5~ on.

really Ive read Ive searched Ive confused myself beyond all recognition!

will 31s just be silly with the 6" lift?

will an 8" rim with 4" BS be fine for 33"s?

Ugh... if i re-gear then I might as well do a locker right? and the install?

Well the lift is happening! but with all this indecision :( she proly wont get shoes any time soon.

Its SOOOOO... hard to tell what wheels people have "fit" under their truck as opposed to what wheels should be on the vehicle in order to be reliable and not wear itself out!

So I could slap on 31"s and hit the trail...

or I could save up another (what 3000$) and get 33s, new gears (4.10~), and a rear locker...

then hit the trail!

Suggestion gentlemen?

There are a lot of people that run 33x12.5 on the stock 15x7 rims. In that pic above, warthogdriver has a 6" superlift and those are 33's on 15x7 Camaro wheels that I think are 4" BS. Keep in mind that the middle number (31x10.5x15) is referring to the section width of the tire and not the tread width. My 31's only have a tread width of about 8" or so. I think an 8" wide wheel would work great with 31" or 33" tires

I've never re-geared or installed a locker so I really can't say how hard the installation is. I have 3.42s turning 31x10.5 and it seems to do alright. Haven't noticed a drop in mileage

I don't think 31's would look silly. In my opinion though, the main goal behind a lift is to make room for bigger tires and there are many people with 31's on just a body lift or tbar/shackle lift. It seems excessive to go all out with the 6" Superlift only to stay with 31's. Again though, that's just my opinion and should have no bearing on what your ultimate decision is. I can understand not wanting to screw up a brand new transmission though.

Go with the 33's and regear it since you have to remove the front diff anyway to install the 6" lift. If you wait to do it afterwards you are going to hate life. lol... 33's with a 15 x 8 is fine. You can get wheels is a 4.5" backspace and it'll look good.

This is an interesting link: 4Lo.com :: Gear Ratio & Tire Size Chart

Basically what it's saying that with 33's you could get away with a 4.11 (Better fuel mileage) or a 4.56 for a little more low end grunt. Great if you're trail riding IMO.

Now it's to look at what your main use for the vehicle will be... stick with your 4.10, 15x8 rims with 4.5" backspacing as Dave said, and if you don't have the dough for 33's yet, maybe a set of 4 used tires for now?

As for gear install: 10-Bolt Rearend Gear Installation - Tech Article - Chevy High Performance Magazine

Ok thanks guys! So... my revised plan will be to try to get the shop to do the re-gear/locker when they do the lift (if i can afford it!). I will proly go with the 4.56 gears and then i will do General Grabber AT2 33 x 12.50-15 on the 8"x15x4"BS cragar style steal rims.

Now... before I bought the truck it had an HD trans put in and may have possibly been re-geared already. (shot in the dark). so my question is: on these trucks with the limited slip (one-tire-fire) how to I get my gear ratio? do i just jack up the drive tire with the front blocked and in neutral and then mark and spin the wheel 2 revolutions? or am i mixing up my methods?

The reason i wonder if the truck has already been re-geared is that it was used for towing, had expensive mods done to it originally (shift kit HD trans, trans cooler) I found a huge aluminum wheel for the spare (best guess it was at least a 31", and the truck has always acted slugish~ish. i could be crazy but i figure it would be worth calculating. let me know?

EDIT: So I think Im starting to understand...

I should have the shop doing the lift do the gears too (if needed, as stated above) for convienence sake? but i can install an arb later myself?(rear only, aluminum front dif :( ) ? Er... Uh I guess I have to swap in a gm 8.5" 10 bolt to find any kind of manual locker that will fit?