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Tire size question.

Dabba

Dabba

1/2 ton status
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First, what was the stock size the k5 came with in 86? right now im running 31 and while they look good, it doesnot look stock. Also ive looked through the pictures and im still confused. Im looking to go with a 4inch tuff country ez ride lift and i wanted to put 35s on it. Some pics it looks as if the front tires are too big for the wells (like if you hit a bump and wheel shot up it would hit the front of the well) and other shots it looks like it clears the well okay. Also if i ahve a 4 inch with 35s will there be any rubbing if im hitting bumps and knockin the crap out of it? Also will it kill me to keep 3.08 with 35s? thanks
 
I believe stock is 30 or 31s. 35s with 4" lift shouldnt rub, but like all things you never know. 3.08s will kill you with 35s unless you have a powerhouse for a motor. Ive got 33s with 4;10s and even that is iffy. I run 2200rpm @ 65mph, but im also running a gutless wonder 305cid.

One thing to look at with tires is the actual size. for example. The toyo 33" M/Ts actually measure 33.1, while the BFG M/T 33" actuall measure 32.4. The Mickey Thompsons Im running now, measure 32.8, close enuff for me. lol
 
i run 33s with no lift and my old 31s looked tiny in the wheelwells. 35s will be tight, but you might get away with it. and yeah, 3.08 and 35 will feel wimpy unless you have a beast of an engine.

this stuff is covered better in many other threads, so look around for more info.
 
35 will prolly rub a bit when your flexing the truck especially while turning moreso at the rear of the fenderwell. I run a 5 inch lift and 35's with slightly stiffer springs and trimmimng is in the near future. 3.08 gears will be rough to deal with and hard on the gas needle too.
 
With a 4" you will have to trim the front to fit 35s if you do any wheelin(specifically the rear of the fender). The rears will clear 35s no problem.
 
You wont rub really on normal driving but if you get much flex going you will rub. I had mine trimmed at a body shop while I was getting a lot of other work done. Took him around 10 minutes.

As for an axle swap, it is probably cheaper to find a set of 10 bolts or 3/4 tons with 4.56s or 4.10s than it is to regear what you have. What tranny do you have?
 
the only reason to regear is your trans will thank you or if not it will die on you. if you can find a set of axles for cheap with a better matched gear ratio its so easy to swap them in.
unbolt the old ones.
instalation is reverse of removal lol

its really that easy.
 
4.56 and 35s is optimum. sometimes its not always an option, so 4.10 would be the next step. its not got the get up and go as 456 but is still not as bad as 3.08.
 
I run a 6" BDS full spring kit. 35x12.5 BFG M/T on 15x10 wheels.
On road, hard bumps, swoops, swells, mud puddles, straight-on, light off-road..... it never hits. When I twist those axles up, I constantly get into the sheetmetal. I have trimmed a bit, but not much.

I am running 10b's both at 4.56 and the rear is LS. 350tbi/700R4/208. I love the power that gets put down.

Also, I have already purchased my 1 ton front axle, am in active search for a rear, and will be looking to off-load my existing setup. Our timing my not work out, but keep you eyes peeled for a situation similar to mine. You could make out with a complete setup and hang on to your own stuff for spares.
 
I have a 700r and run 4.88's and am very happy with it. 4.56 would be equally good with a little less RPM on the highway. Mine turns a hair over 2000 RPMs at 60 MPH with the converter locked up. It definately helps unload the motor and helped out gas mileage a bit when going from the stock 3.42's in my K5. You'll be glad you did it!
 
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Alright sorry to bump my old thread, buttt, i was thinking of just doing the 4 inch with 33's for the better fit. What gear ratio would be good for 33s?
 
http://www.et-studios.com/motorsports/gears/gears.html

try this link and you can play around with diferent ratios. Below are the gear ratios for a 700R4 3.06 being 1st and .70 being O/D, 2.29 is reverse. I always try to shoot for 2000 RPM or so at 60mph for a truck that has the drag of a huge brick so the motor is not lugged down too much on the highway. The stock gearing is normally way more conservative than that. And remember this does not take into account converter slippage. (which there is none of you have a lockup converter)

I'd say 4.56s would get you there, and you'd have a much better crawl ratio than stock also.
700r4
1st gear/3.06,
2nd gear/1.62,
3rd gear/1.00,
4th gear/0.70,
Reverse/2.29
 
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