Gear ratio for 35 inch tires.

[Camar068]

I would definitely go with at least the first green box on that chart. Go with the 2nd if you feel you might increase tire size anytime in the future.

I had 3.73 with 31's and went up to 32". It's a bit weaker beast now.....have to get a little more agressive with the throttle now. I knew I shoulda gone 3.90.

 

[RecklessWOT]

As far as a ok ratio for the 35's, 3.73 I think would be fine.

No way. I'm pretty sure that 1990 has a 700R4, and if it's a V10 it most likely already has 3.73s. With 3.73s and 35s it will be a dog (I have 33s and mine sucks). If you can find 4.27s that'll be pretty close to putting you back at factory gearing (would be spot on if you had 33s). As far as what's commonly available 4.10s would be better than nothing, but I'd personally go with 4.56s to combat that super tall 700r4 gearing and big tires. That's what I bought for my truck though I have yet to put them in.

 

[shiftpro]

That doesn't take into account overdrive though. 4.56 or 4.88 would really be pretty good.

Absolutely...
4.88 gives the option of going taller... like 39s. Most 35" tires are 34.5..
Can't remember the brand but a 39 i measured was 38.25".
If you ever move up to (God forbid) 17 or 18" rims there is a crap load of 39" tire options.

 

[shiftpro]

No way. I'm pretty sure that 1990 has a 700R4, and if it's a V10 it most likely already has 3.73s. With 3.73s and 35s it will be a dog (I have 33s and mine sucks). If you can find 4.27s that'll be pretty close to putting you back at factory gearing (would be spot on if you had 33s). As far as what's commonly available 4.10s would be better than nothing, but I'd personally go with 4.56s to combat that super tall 700r4 gearing and big tires. That's what I bought for my truck though I have yet to put them in.

And to mention, the 700 HATES low rpm torque... so a BB with great bottom end that can spin hwy speeds at 2000 or less rpm with flat melt a 700.

 

[shiftpro]

I have a 91 crew cab with 35’s, 4.56’s were perfect for it. No DRAC mods, it shifted normal like before the lift and felt great driving.

Nice... so your '91 has the 4L80? And the 205 by chance...(holy grail of square body drivelines.) If it has the 4l80 it would also have a slick little
shift controller... which I want to know more about....

 

[Vbb199]

No way. I'm pretty sure that 1990 has a 700R4, and if it's a V10 it most likely already has 3.73s. With 3.73s and 35s it will be a dog (I have 33s and mine sucks). If you can find 4.27s that'll be pretty close to putting you back at factory gearing (would be spot on if you had 33s). As far as what's commonly available 4.10s would be better than nothing, but I'd personally go with 4.56s to combat that super tall 700r4 gearing and big tires. That's what I bought for my truck though I have yet to put them in.

I corrected my statement.
Wasn't considering the 700 in it.

 

[nvrenuf]

Nice... so your '91 has the 4L80? And the 205 by chance...(holy grail of square body drivelines.) If it has the 4l80 it would also have a slick little
shift controller... which I want to know more about....

Sorry, autocorrect got me, that should read as “had”.
Yes I had a 91 V3500 with a 4l80e / 205. I really regret letting it go. I found it about 6 months ago raped & pillaged in Tn, all of the original drivetrain was gone and the dash wiring looked like a tumbleweed.

 

[Vbb199]

Sorry, autocorrect got me, that should read as “had”.
Yes I had a 91 V3500 with a 4l80e / 205. I really regret letting it go. I found it about 6 months ago raped & pillaged in Tn, all of the original drivetrain was gone and the dash wiring looked like a tumbleweed.

I hate it when that happens. I had a 84 k5 that I cut out all the rusty spots in the floor and welded in clean metal, fixed all the wiring, did a 6" lift, had a set of 39.5's on (I didn't know better putting those on 1/2 tons)

Traded it off to a guy, he flipped it not even 24 hours later, traded it to another guy, it now sits up in the mountains about 3 hours away, completely raped of everything. Its a hull and a frame.

 

[bucket]

Sorry, autocorrect got me, that should read as “had”.
Yes I had a 91 V3500 with a 4l80e / 205. I really regret letting it go. I found it about 6 months ago raped & pillaged in Tn, all of the original drivetrain was gone and the dash wiring looked like a tumbleweed.

That sucks. I'd just rather live not knowing what happened to it, lol

 

[nvrenuf]

That sucks. I'd just rather live not knowing what happened to it, lol

I wish I had now. I got the urge to find it and possibly buy it back so I started looking via carfax, that’s when I found it on Craigslist. It’s even got big bro wheels now, everything that made it special because it’s a 91 is gone. It completely killed my desire to get it back.

 

[Shaun Neubert]

Absolutely...
4.88 gives the option of going taller... like 39s. Most 35" tires are 34.5..
Can't remember the brand but a 39 i measured was 38.25".
If you ever move up to (God forbid) 17 or 18" rims there is a crap load of 39" tire options.

I personally think its disgraceful to put big rims on a 4x4. Especially a square body. Just my personal opinion of course. But 35 inch tires were the biggest I could put under mine without a bunch of rub. As for ratio. I'm going to go with the 4.56. It seems to be the best balance of power and economy. If there is such a thing with old sbc.

 

[77 K20]

Well- I'm finding I will probably need to move up to 17s from my 16s. There just isn't much in the way of options. Especially when I'm looking at getting some 8 lug beadlocks. They make 15s then 17s.

 

[Shaun Neubert]

I've never looked into rims much. The 15 inch rims just always seemed to look best to me. Also it maximized the sidewall for reducing tire pressure during maximum traction requirements. Increased rotor diameter is the only reason for bigger rims in my personal opinion.