Whats up everyone, Im building a 1977 F-150 4x4 from frame up. Im looking to build a weekend cruiser that i can take to the the hunting camp to raise hell but would also like to drive it there comfortably, i was looking for suggestions on the gear ratio i should choose, i will be running a 408windsor through a Np435 and Np205 tranfer case and i am considering either a 3.70, 3.89, or 4.10 gears, and 33 inch tires. I would like some good highway manners but would also like to rip it up offroad, if anyone has any suggestions on this combo that would be appreciated. Also i cant find any gear ratios that match up for a 9" and D44, would it matter if they where a little off

 

id go for the 3:70s if you can get a gear set to match close enough, then it will have decent highway manners.

in my own expierience the granny gear and low range was always more than enough to get it done off road in my old 150, and that had 40 inch tires and 3.50 gears

 

+1 i run 38's with 3.50's and a 4 speed and its more then enough, plus i only turn about 1800 rpms at 65

 

Seriously? I run 37's with 4:10's and I wish I had more low end grunt. 1800 is way too low. Your truck must take an hour to get up to 60 mph.

In the OP's case I'd suggest that you use either the 3:89 or 4:10 if you actually want to do any work with the truck or climb a hill or be able to tow. As for the guy with the 38's, you really ought to be running 4:56's at least (4:88's would be better).

Here's a chart for proper ratio's. You can find dozens of these charts if you google gear ratio - tire size. This just happens to be the first I found.

<table class="maintext" align="center" border="1" cellpadding="0" cellspacing="0"><tbody><tr><td align="center" bgcolor="Yellow"> Better Gas Mileage </td> <td align="center" bgcolor="Lime"> Near Factory Ratio </td> <td align="center" bgcolor="Red"> More Power </td> </tr> </tbody></table>
<table class="maintext" align="center" border="0"><tbody><tr> <td>
</td> <td align="center">Gear Ratio</td> </tr> <tr> <td align="center" valign="middle">T
i
r
e


D
i
a
m
e
t
e
r
</td> <td> <table class="maintext" valign="CENTER" align="center" bgcolor="Silver" border="1"> <tbody><tr bgcolor="Aqua"> <td>
</td> <td>
</td> <td>3.31</td> <td>3.42</td> <td>3.55</td> <td>3.73</td> <td>3.91</td> <td>4.11</td> <td>4.27</td> <td>4.56</td> <td>4.88</td> <td>5.13</td> <td>5.29</td> <td>5.38</td> <td>5.71</td> <td>6.17</td> <td>7.17</td> </tr> <tr></tr> <tr> <td bgcolor="Aqua">27"</td> <td>
</td> <td bgcolor="Yellow">2677</td> <td>2766</td> <td bgcolor="Lime">2872</td> <td>3017</td> <td bgcolor="Red">3163</td> <td>3325</td> <td>3454</td> <td>3689</td> <td>3947</td> <td>4150</td> <td>4279</td> <td>4352</td> <td>4619</td> <td>4991</td> <td>5800</td> </tr> <tr> <td bgcolor="Aqua">28"</td> <td>
</td> <td>2582</td> <td bgcolor="Yellow">2668</td> <td>2769</td> <td bgcolor="Lime">2909</td> <td>3050</td> <td bgcolor="Red">3206</td> <td>3331</td> <td>3557</td> <td>3806</td> <td>4001</td> <td>4126</td> <td>4196</td> <td>4454</td> <td>4813</td> <td>5593</td> </tr> <tr> <td bgcolor="Aqua">29"</td> <td>
</td> <td>2493</td> <td>2576</td> <td bgcolor="Yellow">2674</td> <td>2809</td> <td bgcolor="Lime">2945</td> <td>3095</td> <td bgcolor="Red">3216</td> <td>3434</td> <td>3675</td> <td>3863</td> <td>3984</td> <td>4052</td> <td>4300</td> <td>4647</td> <td>5400</td> </tr> <tr> <td bgcolor="Aqua">30"</td> <td>
</td> <td>2410</td> <td>2490</td> <td bgcolor="Yellow">2584</td> <td>2715</td> <td bgcolor="Lime">2846</td> <td>2992</td> <td bgcolor="Red">3109</td> <td>3320</td> <td>3553</td> <td>3735</td> <td>3851</td> <td>3917</td> <td>4157</td> <td>4492</td> <td>5220</td> </tr> <tr> <td bgcolor="Aqua">31"</td> <td>
</td> <td>2332</td> <td>2409</td> <td>2501</td> <td bgcolor="Yellow">2628</td> <td>2755</td> <td bgcolor="Lime">2896</td> <td>3008</td> <td bgcolor="Red">3213</td> <td>3838</td> <td>3614</td> <td>3727</td> <td>3790</td> <td>4023</td> <td>4347</td> <td>5051</td> </tr> <tr> <td bgcolor="Aqua">32"</td> <td>
</td> <td>2259</td> <td>2334</td> <td>2423</td> <td bgcolor="Yellow">2546</td> <td>2696</td> <td bgcolor="Lime">2805</td> <td>2914</td> <td bgcolor="Red">3112</td> <td>3331</td> <td>3501</td> <td>3610</td> <td>3672</td> <td>3897</td> <td>4211</td> <td>4894</td> </tr> <tr> <td bgcolor="Aqua">33"</td> <td>
</td> <td>2191</td> <td>2263</td> <td>2349</td> <td>2469</td> <td bgcolor="Yellow">2588</td> <td>2720</td> <td bgcolor="Lime">2826</td> <td>3018</td> <td bgcolor="Red">3230</td> <td>3395</td> <td>3501</td> <td>3561</td> <td>3779</td> <td>4093</td> <td>4745</td> </tr> <tr> <td bgcolor="Aqua">34"</td> <td>
</td> <td>2126</td> <td>2197</td> <td>2280</td> <td>2396</td> <td>2512</td> <td bgcolor="Yellow">2640</td> <td>2743</td> <td bgcolor="Lime">2929</td> <td>3135</td> <td bgcolor="Red">3295</td> <td>3398</td> <td>3456</td> <td>3668</td> <td>3963</td> <td>4606</td> </tr> <tr> <td bgcolor="Aqua">35"</td> <td>
</td> <td>2065</td> <td>2134</td> <td>2215</td> <td>2328</td> <td>2440</td> <td bgcolor="Yellow">2565</td> <td>2664</td> <td bgcolor="Lime">2845</td> <td>3045</td> <td bgcolor="Red">3201</td> <td>3301</td> <td>3357</td> <td>3563</td> <td>3850</td> <td>4474</td> </tr> <tr> <td bgcolor="Aqua">36"</td> <td>
</td> <td>2008</td> <td>2075</td> <td>2154</td> <td>2263</td> <td>2372</td> <td>2493</td> <td bgcolor="Yellow">2590</td> <td>2766</td> <td bgcolor="Lime">2961</td> <td>3112</td> <td bgcolor="Red">3209</td> <td>3264</td> <td>3464</td> <td>3743</td> <td>4350</td> </tr> <tr> <td bgcolor="Aqua">37"</td> <td>
</td> <td>1954</td> <td>2019</td> <td>2095</td> <td>2203</td> <td>2308</td> <td>2426</td> <td bgcolor="Yellow">2520</td> <td>2692</td> <td bgcolor="Lime">2881</td> <td>3028</td> <td bgcolor="Red">3123</td> <td>3176</td> <td>3370</td> <td>3642</td> <td>4243</td> </tr> <tr> <td bgcolor="Aqua">38"</td> <td>
</td> <td>1902</td> <td>1966</td> <td>2040</td> <td>2144</td> <td>2247</td> <td>2362</td> <td>2454</td> <td bgcolor="Yellow">2621</td> <td>2805</td> <td bgcolor="Lime">2948</td> <td>3040</td> <td bgcolor="Red">3092</td> <td>3282</td> <td>3546</td> <td>4121</td> </tr> <tr> <td bgcolor="Aqua">39"</td> <td>
</td> <td>1854</td> <td>1915</td> <td>1988</td> <td>2089</td> <td>2190</td> <td>2302</td> <td>2391</td> <td bgcolor="Yellow">2554</td> <td>2733</td> <td bgcolor="Lime">2873</td> <td>2962</td> <td bgcolor="Red">3013</td> <td>3198</td> <td>3455</td> <td>4015</td> </tr> <tr> <td bgcolor="Aqua">40"</td> <td>
</td> <td>1807</td> <td>1867</td> <td>1938</td> <td>2037</td> <td>2135</td> <td>2244</td> <td>2331</td> <td>2490</td> <td bgcolor="Yellow">2664</td> <td>2801</td> <td bgcolor="Lime">2888</td> <td>2937</td> <td bgcolor="Red">3118</td> <td>3369</td> <td>3915</td> </tr> <tr> <td bgcolor="Aqua">41"</td> <td>
</td> <td>1763</td> <td>1822</td> <td>1891</td> <td>1987</td> <td>2083</td> <td>2189</td> <td>2275</td> <td>2429</td> <td bgcolor="Yellow">2599</td> <td>2733</td> <td bgcolor="Lime">2818</td> <td>2866</td> <td bgcolor="Red">3042</td> <td>3287</td> <td>3819</td> </tr> <tr> <td bgcolor="Aqua">42"</td> <td>
</td> <td>1721</td> <td>1778</td> <td>1846</td> <td>1940</td> <td>2033</td> <td>2137</td> <td>2220</td> <td>2371</td> <td>2538</td> <td bgcolor="Yellow">2668</td> <td>2751</td> <td bgcolor="Lime">2798</td> <td>2969</td> <td bgcolor="Red">3208</td> <td>3728</td> </tr> <tr> <td bgcolor="Aqua">43"</td> <td>
</td> <td>1681</td> <td>1737</td> <td>1803</td> <td>1894</td> <td>1986</td> <td>2087</td> <td>2169</td> <td>2316</td> <td>2479</td> <td bgcolor="Yellow">2606</td> <td>2687</td> <td bgcolor="Lime">2733</td> <td>2900</td> <td bgcolor="Red">3134</td> <td>3642</td> </tr> <tr> <td bgcolor="Aqua">44"</td> <td>
</td> <td>1643</td> <td>1698</td> <td>1762</td> <td>1851</td> <td>1941</td> <td>2040</td> <td>2119</td> <td>2263</td> <td>2422</td> <td>2546</td> <td bgcolor="Yellow">2626</td> <td>2670</td> <td bgcolor="Lime">2834</td> <td>3063</td> <td bgcolor="Red">3559</td></tr></tbody></table></td></tr></tbody></table>

 

Not really, my truck will get up and ride, it help that it that has a 400 thats .030 over and has 9.5 to 1 compression with a comp cams 268h and headers and an eldebrock intake and an msd distributor and 6al ignition box

 

wear a heavier boot. do you have an automatic?

 

Yes I do have an auto. I also have a built 390. I have tons of power from the motor (I have no problem smoking the tires), but I'd like to have 4:88's in my axles. However, I actually use my truck to pull trailers and climb hills, unlike the 2 of you running 3:50's and big tires. I'd love to put my truck up against either of yours and show you what proper gearing does for you.

Also, they don't make those gear ratio charts on a whim. I'm actually backing up my statements with facts. You can find those charts all over the internet and usually at any offroad company you do business with. Those charts don't lie. You can't run 38's or 40's with 3:50's and actually have any available power. The only reason for running like that is because you're too cheap to buy new gears when you lift your truck.

 

well im glad you cleared that up because facts are what its all about


now fact 1. gearing can do wonders
fact 2. you have an automatic
fact 3. my first gear is almost twice as deep as yours
fact 4. i love to put my truck up against yours and show you what spending money got you
fact 5. the op asked for suggestions i gave him a FACTUAL experience of mine

 

i live in florida so i dont have hills to climb and the 3.50 work great for mud cuz you get alot of wheel speed, heres a video of my truck doing a burn out, and thats with my racecars old 2 bbl carb before i got a holly 750
http://www.youtube.com/watch?v=W0hnnqzI7CQ
http://www.youtube.com/watch?v=HhP7ymFhJ_E

 

I'm responding in red...

In a puddle of water? Really? That's pretty silly. I can get my bicycle to burnout in a puddle too, but that doesn't really mean that it's got power. You kind of did yourself a disservice there...

 

i highly doubt 4.88s will blow my mind
i dont care how much power your auto doesnt rob, we are talking gearing
i dont care about gearing in the axle. gear ratios are gear ratios the only difference is the strain on the drivetrain
if gears arent that expensive why are you preaching 4.88s and yet still running 4.10s -to cheap?

as far as me giving my opinion thats what he wanted-

however it is a FACT that it worked for ME

so how about you help the op instead of bicker with guys whom you dont know

 

I did help him. I gave my opinion and provided a chart with gear ratios/tire sizes so that he could make an educated decision instead of only getting opinions.

For your info:
np435
1st - 4:78:1
2nd - 2:39:1
3rd - 1:37:1
4th - 1:1

c6
1st - 2.46:1
2nd - 1.46:1
3rd - 1:1

As you can see, the only real gear ratio difference is the addition of a granny gear. That makes a difference in your overall gear ratio, but only in that one gear. Once you shift to 2nd we're at the same place. Granny gear is only usable typically under 15 mph and then you shift. Once you do, my gearing is much better than what you're running.

And yes, I'm too cheap - to do it twice. I'm looking for a Dana 60 for the front in place of my 44. I will swap gears when I have the axle I want instead of throwing $400 away on gears for what I currently have. Furthermore, I already spent the money once when I originally fitted bigger tires. My first set were 35's and the 4:10's worked about right then. Actually, they work pretty well now, I just want more grunt.

 

alright now we're getting somewhere

with the trans gear ratios layed out there you can see why i liked my big tires low 1st setup and why it workied for me

with the stock size tires that granny gear was utterly useless
when i put the big tires on it made every gear feel useable

and i still had low range

see now, its all good when there's no bickering and FWIW i Can climb hills till my carb runs out of fuel and i Can haul a trailer, however i never recomend pulling a trailer with a lifted truck

while i think your chart is a little off, i do understand what your saying.

but the op wants the best of both worlds and that chart shows no low range

 

It is always very interesting that the guys that say "it works for me" say it as a last resort or in some sort of relief that the vehicle actually rolls around under its own power after the little voice inside said that it probably would not work.
A proper gear ratio provides a mechanical advantage that most take for granted or insist that the low first gear of the 4 speed can make up for.
Believe me that an NP 435 in the mud has little use for first / low gear. regardless of the ratio, that first gear is too low for any kind of wheel speed. Crawling around, and running tight trails or steep decends and the 435 is optimum, but to rely on its low gear for a lack of proper axle ratios is a stretch, a real stretch.
Second gear is too tall without a decent axle gear, and low gear is far to low to trun the tires with reasonable speed.
Deep gears off road are king and the only compromise is highway rpm. For me this is not a compromise. 33" tires would be great with 4.10 gears even on the highway. I have run 4.56's with 33's and stepped up to 35's. While I did feel a difference and a loss of performance, I could not justify the expense of yet another gear change.
After the tire size was increased, (40's) the gears naturally had to get better, and 5.13's what it had to be.
For my truck with 44's, I wish I could run deeper than 5.38's. Even with a rather large engine, (557 CI BBF and nitrous BTW) having the mechanical advantage of gears is a real plus.

Most of the time owners use the term, "it gets my by", or "it works for me" but there are not too many guys that have put a set of gears in with the optimun ratio and said man, this is way toooo much gear. I wish I had those 3.55's.
I mean even with a fire breather for an engine, trying to get a tire motivated without some gears is a real pain, and can be embarassing.

If I were a betting man and had to wager on one of the trucks, I would bet on the one with the gears, even if the other had more motor.

Shamelss is right on the money here. The vehicle with the optimun ratio in the axles will have advantages all around.

If the rpm is too high at 70 mph, slow down to 65 or even 62 mph. You will drop engine rpm, and will save some gas too.

Ive never run a vehicle with too much gear. I mean geez what do guys with 44" tires do when they are running rockwell axles? 6.72:1 sounds steep right? Nope, it is an eye opening experience.

After the guys that "get by" install some real gears, they often wonder what they were doing, or how thau ever survived running such poor ratios.
I was there once. Glad I got out of that phase. Never looked back either, and havenever run a silly ratio again. Its not all about highway rpm. One has to consider getting the vehicle motivated before the highway variable is even in play.

 

Thank you 75F350 for backing me up on this. I was hoping you'd stop by and explain it in your words. You made my point more eloquently than I had and I hope that this ends the debate.