Stock rear gear ratio info
1. Does anyone know what the available (stock) rear gear ratios were for a 1971 Chevrolet C10 truck?
+++++++++++++++ 2. I know there were optional gear ratios, but does anyone know what the standard gear ratio would likely have been for: 1971 Chevrolet C10 (non Cheyenne) 350 V-8, 4V carb TH350 automatic transmission 1/2 ton, long bed 2WD (non 4WD) 5-lug wheels leaf spring rearend factory A/C |
Re: Stock rear gear ratio info
3.07
If had a 3 or 4-speed manual, it would've had 3.73, 4.11, or in some rare cases, 4.56. |
Re: Stock rear gear ratio info
I have a '70 and the SPID (which I looked at last night) said 4:11.
|
Re: Stock rear gear ratio info
With the 350 engine, 3.08 (3.07) was the standard ratio.
|
Re: Stock rear gear ratio info
Anyone happen to have an original type chart that shows the available rear gear ratios?
|
Re: Stock rear gear ratio info
I don't have a chart, but 3.07/3.08 is standard for automatic trucks. 3.54 if it was a 3/4 ton. 3.73 was standard for manuals or I believe 4.10 for 3/4 tons.
|
Re: Stock rear gear ratio info
For what it's worth, I pulled the rearend cover and looked at the ring/pinion gears. The math indicates that my truck has a 3.07:1 ratio with an open differential ... just like 68350 stated.
|
Re: Stock rear gear ratio info
Base 1/2 ton trucks got a 3.73. Most 3 speeds were also 3.73. 3.07 was the norm for 4 speeds, although if memory serves, a 307 with a 4 speed still got the 3.73
As for the original question... 350 with an auto got 3.07 gears unless optioned in a 1/2 ton. Most of whats been said here is acurate, although, 4.56 I don't think was ever in a 1/2 ton, 3/4 tons didn't get a 3.54 with a small block, that was a big block gear. Small blocks and inlines would get a 4.57, 4.10, or a 5.13. |
Re: Stock rear gear ratio info
this is a thread for a 72, but at least it still all matchs whats been said and its cool to see original style brochure
http://67-72chevytrucks.com/vboard/s...d.php?t=424698 oh yeah be glad u don't have 5.13s they suck fuel, like a rusty fuel tank with no bottom:lol: |
Re: Stock rear gear ratio info
I think it most likely has 3.73 or 4.11
|
Re: Stock rear gear ratio info
Quote:
Quote:
|
Re: Stock rear gear ratio info
Quote:
|
Re: Stock rear gear ratio info
Hello all, new guy here. I am considering buying a '67 C20 for a daily driver and curious as to the gearing. As stated its a 67 with a 327 and 3 speed auto.
Posted via Mobile Device |
Re: Stock rear gear ratio info
Quote:
|
Re: Stock rear gear ratio info
what exactly is this "trailor towing package", what's the RPO on that?
|
Re: Stock rear gear ratio info
1/2 ton
12 bolt: 3.07, 3.73, 4.11, 4.56 3/4 ton corp/eaton 10 bolt: 4.10, 4.57, 5:13, 6:13 Dana 60: 3.54 the 3.54 was standard for the big block 400 as it didn't need as much gearing. the 3.07 was pretty standard on the 1/2 ton with an auto unless you ordered otherwise. my 72 burb c20 automatically came with a 4.57 because it is 2wd and has a manual 3 on the tree. the 4x4 burb got the 4.10 normally as did most c/k 3/4 ton pickups as they are lighter. i put a 4.10 third member in my burb because it was an easy swap and the 4.57 is a little too low once you get rolling. with a q-jet in place of the 2bbl the 307 is much spunkier now because of the quick response small primaries and the extra air flow potential. i picked up a 66-69 saginaw-borg warner overdrive trans (my rig is a 3 on the tree) and that will give me a far better highway ratio than a straight 3.07.....so i get the best of both worlds. |
Re: Stock rear gear ratio info
somewhat acurate
|
Re: Stock rear gear ratio info
Quote:
|
Re: Stock rear gear ratio info
Quote:
|
Re: Stock rear gear ratio info
yeah....i forgot that you could get a big block in the 1/2 ton trucks.....like a bare bones precursor to a chevy SS of the early 90's. even with the 400bb, a 3.07 is still kinda soft if you do any serious towing because it only has 30 more ft-lbs than the 350 according to my 72 burb brochure. however it would be perfect for a modern diesel swap (you'd still want a mild overdrive gear with a diesel). perhaps you could special order a 3.73 or a 4.11 if you needed it for towing. there was also a 4.56 available on 3/4 ton trucks and that was for the the dana 60 without the big block as the 4.57 is the corp/eaton. 3.73 was standard on all 1/2 ton burbs and the 4.10 was an option available for the K20 burbs.
i like a 3.42 to 3.73 on a 1/2 ton and a 3.73 to 4.11 range on a 3/4 ton (unless i had huge diameter tires). an overdrive is the other piece of the puzzle and there are several bolt-in routes you can go with depending on what model/type of trans you have to begin with! |
Re: Stock rear gear ratio info
you are still off. 3.73 was not standard on all burbs.
The gear ratio depended on the engine, trans, and the size of truck (10/20/30) and also it depended on what rear axle it was equipped with. in 2 wheel drive 1/2 tons, on the base model, either CE or CS trucks, the standard gear was 3.73. However, throw in an optional engine, or optional tranny, and that may not be the case. Same for a C/20. The 4.57 was standard, but a 4.10 was included in certian engine/tranny combos. You could opt for any of the avalible gear ratios, but sometimes you couldn't get that gear with certian engine or trans or even rear axle options. |
Re: Stock rear gear ratio info
i was talking standard equipment (base engine, trans, etc). other gears options are obviously dependent on configuration/package. GM doesn't always play by its own rules and who is to know if a previous owner didn't do some customizing?
look at the gas tank size on the burb. according to the brochure all C/K 10/20 came with a 21 gallon tank, and i believe that because it took about that to fill it up after i ran out of gas once. but according to the glove box handbook the C20 and K20 burb should have a 23 gallon tank. just 2 extra gallons (and an extra part number) doesn't make much sense from a marketing and money making standpoint. they had the 45 gal tavel tank for those needing more capacity! |
Re: Stock rear gear ratio info
Quote:
Jack one rear wheel off the ground, put the transmission in neutral and the parking brake off. Put matching marks on the pinion yoke and differential housing. Turn the wheel exactly TWO revolutions and count how many times the driveshaft turns, estimating any fractional turn as closely as possible. That number is your axle ratio. If the wheel is difficult or impossible to turn, you may have posi. In that case, jack both rear wheels off the ground and turn either of them only ONE revolution. Count the driveshaft turns the same way as for an open rear. Ray |
Re: Stock rear gear ratio info
Quote:
|
Re: Stock rear gear ratio info
Wanted to bring up this subject again...my truck SPID is a factory TH350 trans with a 307 engine. Likely rear gear ratio? It seems that most of the 350 engines were 3.08 gear ratio with automatic, didn't know if it would be different on a 307 engine?
Thanks! |
All times are GMT -4. The time now is 06:49 AM. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com