for all of those rockin' a 4 speed granny low trans!

[chevytruckclassics]

how do they go down the road? curious to know since mine will be on the road son. is it screaming at 55 or not that bad? give me feedback!

[Lattimer]

I don't have one, but I have driven a truck with one a lot. 1st is generally not going to be used unless you are moving a really head load, backing a boat down a ramp, etc.

4th is 1:1, so how it goes in high is dependent on what rear you have. With a 3:73 or higher highway speeds are do-able. Anything 4:10, 4:56, etc. without overdrive will be too low for reasonable rpm's on the hiway.

The old farm truck I learned to drive in had 4:56 gears and the granny low 4-speed, top speed was about 60 and it was screaming. However, we used to put in in low, get out, and follow it across the field tossing hay bales to the guy in the back stacking them. It would idle along at easy walking speed.

[WorkinLonghorn]

If it is a stock 4 spd it has a 1:1 4th gear so you would be more interested in what differential gearing you have and what size tires.
I have 3.73 gears and 31" tires and 60 MPH is something like 2300RPM IIRC. At 70 it seems to be reving too high for my liking.

[GASoline71]

As stated above... it will basically be a 3-speed unless you are needing the low end grunt.

I had one in a 1979 GMC K2500. Loved it. I had 35" tires on mine with 4:11's front and rear. Never had a tach in it, so I don't know what the RPM's were. But it didn't "R-out" too bad at highway speed.

Gary

[stomper]

Previous posts pretty much said it all:

1:1 4th gear so it's no different than any other NON overdrive trans on the highway. Highway RPM will depend on your rear gear and tire height just like any other.

4 spd trucks typically have a lower rear gear (my step had 4.11's)

1st is useless unless you have a heavy load or want to crawl for some reason. It's basically a 3sp with a super low 1st gear. Street driving you start in 2nd.

I drove my step to work for the first time after 9 months of working on it in the garage. The truck 4spd is going to get old quick for the commute.

[SS Tim]

You can just plug your numbers in. Since 3.73 was the ratio for 67-68 K10 trucks it is if everything is stock a matter of tire size.
http://www.summitracing.com/expertad...tio-calculator

[TBONE1964]

I have one in my 64 and I love it. However, I don't ever drive it much over 60 and cruising around town between 35 and 50 is a lot of fun. I have 3:73 rear gear 235/70/16 tires. yes, the first gear is a stump puller but that is all it is really good for, no need for regular driving.

[72chevyfleet]

i have one with 4.10s in my 72 its doing almost 3000 doing 60 yeah its annoying but runs great and tows/hauls like a beast

[Don Quixote]

I run one in my truck with a 14 bolt rear running 3.73s. I love my setup. I won't cruise above about 65 regardless of the speed limit but I do get plenty of use of of my granny gear when I am pulling my cargo trailer. It is about 12,000lb fully loaded and my clutch thanks me every time I use it with the trailer while my friends laugh at me for running through the first 3 gears before I get through the intersection.

It is a very tough and heavy transmission and I applaud anyone smart enough to run one. They are not very user friendly although I find that mine floats gears beautifully as long as I take my time. I just had mine rebuilt a few months ago, first time ever and only had to change the bearings, that's with 440,000 hard earned miles.

[RichardJ]

3.54 gears, LT285/70R17 tires. 75 mph is no problem. I didn't loose as much pulling power over the old 4.56 gears as I had feared I might. It still pulls well on the hills as long as traffic is flowing. If I get held up on a hill, 3rd gear is a long way down there. Then you remember it's a six.

[Don Quixote]

When I'm pulling, 3rd really is a long way down. Two choices, grunt or whine. A ranger box would be nice but it is just not worth the time and money.

I must say, 3.54s are pretty short for a 292. I ran a 292 (which I loved, by the way) with 4.56, then 4.11, then to the 3.73 I run now. I have a tough time with my trailer with my low end 350. I just can't complain because I refuse to go bigger. If anything, if the price were right, I would go back to the 292.

Oh yeah, this is about the rock crusher. I'd still say go for it. I won't switch it for anything.

[aclay17]

I have one in my '67 LWB. I'm running what I think are 3.73 I run 65 at 2300rpm's. I have a 250 inline with 1bbl carb and got 18 mpg on the Hot Rod Power Tour.
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[Shyguy]

I had a '67 C-20 Chevy with a SM-420 and L6 250 , a '71 C-10 with a SM-465 and 350 V-8, a '72 GMC with a SM-465 and a 350 V-8, I now have a '67 C-10 Chevy with a SM-465 and 454 and a '75 C-30 dually with a NP-435 and a 350 V-8.

Now you may be able to tell I like the old 4 speeds best for what I want a truck for.

I can see how others would like the ease of driving with an automatic, because the truck I use for most of the traveling and towing distances is a '92 K-3500 with a 4L8e automatic and a 454.

[Daner]

Just don't be in a hurry to get anywhere and you'll be fine whatever your combo is.

[special-K]

My 4spds go down the road the same as my automatics and 3spds...1:1. That said,manual equipped trucks came with lower gears than automatics,unless equipped with optional gears. Mine have mostly been 4wds,so the automatics had 4.10 like most manuals I've had. And they went down the road the same.

[bobs409]

You do have to "aquire" a taste for them though. When I first started driving mine, it felt so wierd the way the gear ratio is but I was told all the old trucks were the same. 1st is all but useless which I knew, second is cool but third you have to wind out longer before hitting 4th. (that's the weird ratio I mentioned) First thing you'll be thinking is who the hell designed these gear ratios! LOL

My truck is a V8 and has a 4.10 but still doesn't like big hills. These transmissions aren't for drag racing, that's for sure.

All in all though, I love it. Soon I'll be driving another one just like it only this will be a 1 ton wrecker!

[PanelDeland]

I'll add another comment.Though I don't have the 4 speed,I've driven plenty of them.If you've never lived in Farm/Ranch country or you're younger than about 40,you've probably never driven much that hasn't had an OD tranny of some sort.Trucks from this era were seldom driven over 70 and many less than that.They ran higher RPM's to get work done.Most people aren't used to the feel of a vehicle that runs these higher RPM's.It's obviously harder on an engne to run these sustaioned RPM's and it's certainly less fuel efficient but that's they way they were built.There are plenty on here who have done various things to improve the driveability.Just things to keep in mind about how they drove from the factory.

[TonyJohnson]

4.11s with 33s is pretty nasty at 70. 55 isn't so bad. Off-road suspension doesn't help. On the interstate, you can hear it sucking gas... lol

[special-K]

It's funny how standards change. When these trucks were built and driven daily the national interstate speed limit was a minimum of 70 mph. Then,just as today that was seen as a suggestion and the general flow was at least 70. And,these trucks were rolling right along with the rest. Many muscle cars were ordered with 4.10s and their tires were shorter than any truck's,so they were winding out more than the trucks. Now we're used to the low drone of an O/D equipped vehicle,which used to be a rare exception back then,and we fear we'll blow our motors up. I've driven trucks cross-country more times than I can count,and none had O/D. I've slowed to 60-65 (but still find myself creeping up to 70) in the slow lane these days in my 4.10/31" tire K2500 but only because fuel is a major expense. But I get 12.5 mpg wherever I go,whatever roads I take,and many newer trucks with O/D can't beat that. The thing to consider is I spent no extra money to get the mileage I do and that buys a lot of fuel.

[soxplayer]

5:13 gear, 250 six and 235/80 16 tires. Sounds busy above 45 but it will run all day at 65 pulling a 3600 lb car on the tow dolly. It runs great up to 75 but the tack reads 4200 and I don't like to keep the revs that high for long. I only use low for maneuvering or shaking loose a big load on a steep hill.

[1972RedNeck]

I would like to stick a ranger overdrive box in front of one. You would then have an 8 speed and wouldn't have that 3-4 jump.

[Shyguy]

If I think real hard I remember way back in late 1970's I had a '72 3/4 ton GMC with a 350 V-8 and a SM-465.

It use to run 65 and 70 with out straining, of course it did not have a tac and I was use to the sound of a truck. The rearend had 4.1? gears running stock tires.

I pulled a 26 ft cabin cruiser almost every weekend about 50 miles and launched it in Sacramento River Delta, the granny low sure helped a lot when putting the boat in the water and taking it out.

[pritch]

My green '68 has one, 250 motor, 3.73's and pretty close to stock-height tires (judging by my speedo is pretty close) On the flat I can do 70 all day long, but at the altitude here, she gets winded in the hills.

[Don Quixote]

I would like a Ranger box as well but if I rebuild a trans for 500 bucks, why would I spend 1500 on a box with 2 gears?
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[Madtat]

Not to hijack this thread but...
I have the stock 4spd "granny" in my 70 stepper. HATE IT! sure it will pull an A1 out of a ditch but I want to go automatic. Any idea of what an excellent working 4 speed is worth?