Ideal Gearing for AD truck, and what to get

[Coach529]

Looking for some info.

Right now I am running a 216 with a 4 speed. Long term (within a year or so) I hope to replace it with a 235 or 250, mated to a T-5.

Uses will be daily driver in town, occasional jaunt on Interstate. Maybe towing a small enclosed trailer in town.....

I am shopping for a rear end right now. Would rather only do this install once so I am looking for what would be best one I install a new motor and OD tranny. What gear ratio should I shoot for?

Also what is the ideal rear end to achieve this?

S-10 4 x 4 rear ends are said to be a little narrow. Could work with spacers?

F Body cars?

[NEWFISHER]

I'm tossing in my opinion and suggesting 3:73's. Basing off of other builds with an inline and T5.

[Coach529]

Originally Posted by NEWFISHER

I'm tossing in my opinion and suggesting 3:73's. Basing off of other builds with an inline and T5.

That is kind of what I am leaning towards. Might be geared a little low until I get the OD tranny....but should rock after that.

[NEWFISHER]

Originally Posted by Coach529

That is kind of what I am leaning towards. Might be geared a little low until I get the OD tranny....but should rock after that.

My RR ratio was 3:08 and I swapped in the 3:73 rear a month before the 700r4 went in. It wasn't bad, definately a "right laner" on the highway, but do-able. Just did'nt take it more than 40 miles on the freeway at 55 mph.

Whats your ratio now?

[mechanixman]

NewFisher

What motor and tranny are you using?
I'm thinking about 3.73 gears, and I'm going to run a 400 small block, and a T-56 transmission. Should I shoot for a lower gear ratio? I'm hitting highway speeds daily, and I want something that I won't have to worry about top speed too much. But I want a ratio high enough, that I can take it down to the strip, and make a few passes.

[jackson]

Originally Posted by Coach529

Looking for some info.

Right now I am running a 216 with a 4 speed. Long term (within a year or so) I hope to replace it with a 235 or 250, mated to a T-5.

Uses will be daily driver in town, occasional jaunt on Interstate. Maybe towing a small enclosed trailer in town.....

I am shopping for a rear end right now. Would rather only do this install once so I am looking for what would be best one I install a new motor and OD tranny. What gear ratio should I shoot for?

Also what is the ideal rear end to achieve this?

S-10 4 x 4 rear ends are said to be a little narrow. Could work with spacers?

F Body cars?

i put a s10 rearend out of a 4 wd blaser under my ad truck .8" wheel 4 1/2 backspacing. fits like a glove

[Coach529]

Originally Posted by jackson

i put a s10 rearend out of a 4 wd blaser under my ad truck .8" wheel 4 1/2 backspacing. fits like a glove

hmm......now you got me thinking.

That is a pretty standard backspacing I think.....my wheels will not be that wide, but I will probably run 7".

[BlueJeep]

Originally Posted by Coach529

hmm......now you got me thinking.

That is a pretty standard backspacing I think.....my wheels will not be that wide, but I will probably run 7".

I ran a 4wd s10 rear axle in mine with 1" spacers to allow me to clear the bed sides with stock 2wd s10 wheels (15x7, 4" backspacing). It's not an accurate comparison, but I was running 235/75R15 tires with a 4.3 V6, overdrive transmission, and 3.73's. That ratio with that size tire for the 262ci engine (220K miles) was great.

The drum brake s10 rear is 59.5" wide, with .625" pinion offset to the passenger side. Quite a few 4wd s10's had 3.73's.

[Coach529]

Originally Posted by BlueJeep

I ran a 4wd s10 rear axle in mine with 1" spacers to allow me to clear the bed sides with stock 2wd s10 wheels (15x7, 4" backspacing). It's not an accurate comparison, but I was running 235/75R15 tires with a 4.3 V6, overdrive transmission, and 3.73's. That ratio with that size tire for the 262ci engine (220K miles) was great.

The drum brake s10 rear is 59.5" wide, with .625" pinion offset to the passenger side. Quite a few 4wd s10's had 3.73's.

Thanks for the info......BTW....nice truck!!

[NEWFISHER]

Mines a little different....warmed over 250 stovebolt, 700r4 and a 3:73 complete from a 68 c10. I think the 3:73 is a great all around ratio within a bunch of drivetrain combinations. Stock 350/th350, 383/th400, inliner with a 700r4, 454 with a 700r4 or a 400 etc. There will be those who read the words " track" or "pull" and immediately jump on the 4:10 ratio ( which I have in 2 trucks-454 dually 4l80 and 5.3 4l60 2x crew) and its a ratio designed for a purpose just like the 3:73. Yes , tire size plays into this also as does how the engine was set up if you are going to really get into the topic. It comes down to what YOU do with it mostly. Will a torquey big block/400 combo with a 4:10 drive at highway speeds , sure. Will a mild 327/ T5 with 3:73's be fun at the track or pull the boat to the lake occasionally , sure. You will get better milage with a smaller numeric number and better grunt from a larger one is what it boils down to. Where do you come in in that equation? The best thing to do is to ride/drive as many like vehicles with different combo's ask questions to the owners and FEEL what is right for your specific driving needs, everything else is Lazy boy quarterbacking and trying to make sense of graphs and calculations.

My personal situation is: I want a cool retro somewhat OG engine, but want 4 auto gears because I drive over 75 miles a day round trip, but want to pull our 20' 1960 Avion trailer on the weekends. I want good fuel milage, decent power, good looks, ability to yank a trailer over a hill and haul my buddies TO THE RACE TRACK but not compete in it

So yes, I want the best of all worlds too. Sorry to bust your thread Coach

[Coach529]

Originally Posted by NEWFISHER

Mines a little different....warmed over 250 stovebolt, 700r4 and a 3:73 complete from a 68 c10. I think the 3:73 is a great all around ratio within a bunch of drivetrain combinations. Stock 350/th350, 383/th400, inliner with a 700r4, 454 with a 700r4 or a 400 etc. There will be those who read the words " track" or "pull" and immediately jump on the 4:10 ratio ( which I have in 2 trucks-454 dually 4l80 and 5.3 4l60 2x crew) and its a ratio designed for a purpose just like the 3:73. Yes , tire size plays into this also as does how the engine was set up if you are going to really get into the topic. It comes down to what YOU do with it mostly. Will a torquey big block/400 combo with a 4:10 drive at highway speeds , sure. Will a mild 327/ T5 with 3:73's be fun at the track or pull the boat to the lake occasionally , sure. You will get better milage with a smaller numeric number and better grunt from a larger one is what it boils down to. Where do you come in in that equation? The best thing to do is to ride/drive as many like vehicles with different combo's ask questions to the owners and FEEL what is right for your specific driving needs, everything else is Lazy boy quarterbacking and trying to make sense of graphs and calculations.

My personal situation is: I want a cool retro somewhat OG engine, but want 4 auto gears because I drive over 75 miles a day round trip, but want to pull our 20' 1960 Avion trailer on the weekends. I want good fuel milage, decent power, good looks, ability to yank a trailer over a hill and haul my buddies TO THE RACE TRACK but not compete in it

So yes, I want the best of all worlds too. Sorry to bust your thread Coach

All about info.........no problem. Thanks for sharing.

Do you recall the track width of the C10 rear end you used?

[NEWFISHER]

Originally Posted by Coach529

All about info.........no problem. Thanks for sharing.

Do you recall the track width of the C10 rear end you used?

I'm thinking 62? I measured both and the 67-68-69 are only 1/2 wider ( 1/4 per side and also 6 lug, same ujoint etc) than the older ones.

[Coach529]

Wow....so that is exactly the same as a 47-54. Interesting.

[NEWFISHER]

Originally Posted by Coach529

Wow....so that is exactly the same as a 47-54. Interesting.

1/2 wider wms ( wheel mount surface) to wms, bigger bendix style brakes etc so must have been 62 1/2
Mine had a Dana 45 ( google it) wierd locking style like a dana 44 , but couldnt get parts for it. The 68 had a 1310 ujoint and drive shaft bolted right up. When I swapped the 700r4 I used a driveshaft out of a 92 s10 blazer 4dr 4x4 rear and a "conversion joint " to 1310, bolted right in after centering the axle in the wheel well and locating the leaf pin at center vs. forward like stock.