Took the 70 Longhorn on a road trip...

[Ken B]

Every year for the past 7 yrs. my son and myself go to an all Wheel Horse garden tractor show for 3 days in Pa. Its about a 5 hr. ride from my house. This is the first time taking my all original C30 Longhorn The Longhorn has a new Goodwrench 350 in it, an sm465 4-speed and 410 gears. I kept my rpm's right around 2600 most of the time, sometimes a little higher sometimes a little lower. At 2600 rpm I'm doing about 62-63 mph. In total I probably had about 1200 pounds in the bed between two tractors and camping gear. The truck didn't skip a beat and ran awesome. I wouldn't mind swapping the rear out to a 373 rear to cut the rpm's down a little and save some gas, maybe even be able to cruise around 68-70 mph so I'm not holding up my buddies in their trucks who also go to the show. My question is, what rear end would be a direct bolt in if any? My truck has rear leaf springs. Fuel mileage was right around 10 mpg, maybe. Thanks for any suggestions.

[mrtoni]

Are you sure you have 4.11's or is that listed on the SPID? My 3.73's run about 3000 rpm at 60 mph so I tach higher than you. I bet your gears have been swapped at some point. Matt

[Coley]

Ken
It might be worthwhile to query a reputable shop on what it would take to swap out the 4:10 gear set you have to a 3:73 or similar.
Often the amount of work, time and 'unknown factor' in trying to completely change out the rear end of the truck is not worth it vs. just having a new set put in your existing housing.
Given the fact that the truck is a longhorn means it probably has a pretty heavy duty diff in it...but without dual wheels. That might be a little harder to find?
....regardless, maybe worth getting a quote on for comparison purposes...food for thought.

All Good
Coley

[Ken B]

From what I have been told the only gears that came in the Eaton rear end that I have are 4.10's or 4.56's. I think they are the only gears you can put in this rear?

[Coley]

If that is the case...then maybe a downsized 'regular' 8 bolt-3/4 ton rear would do the job...although perhaps not quite as robust as the original.
I'm pretty sure the stock 3/4 tons had a 3.54:1 ratio available, although not overly common.....and generally associated with the 396/400 Big block trucks while the 350 c.i 3/4 ton trucks had the 4:10 I think.

All Good
Coley

[Steven R]

does your diff still have that little tag on the rear diff cover stating what gears are in your diff, (that is if they have not been change by a PO)

I am interested as my longhorn c25 also says it 4.10 gears and wanted to swap them out so keep us posted as to what you do and how it work out pls.

[Mike C]

You can get a Dana 60 with 3.54 gears from a big block 70-72 truck (maybe earlier as well). Most GMC's were leaf springs. But bolt in that's about as "highway" as it gets.

Big tall tires in the back help as well. I ran 265 75 16 on my 70 GMC big block truck and it had the 3.54 diff. It cruised nicely at 65 with the ac on but I never tached it.

What tires do you have now? I'd guess a 215 85 16 probably close to stock tire size and you could go to a 235 85 16 which would knock off a few more revs.

[Ken B]

The rear gears are definitely 410's. I have the original invoice and they are listed on it. I bought the truck from the original owner and he never had them changed. The tires are 235/85r 16's. My 69 Chevelle has 373's on a 15 inch rim and it turns 3000 rpm's at 60..

[Mike C]

Keep your eye out for a leaf spring Dana 60 from a big block truck it should have the 3.54. That will lower rpm about 15% which would make all the difference I bet.

Randy's Ring & Pinion made some 3.90 gears for the Eaton years ago but they have not been available for awhile.

The 235 85 16 is about the same height as the 265 75 16 so no gain there.

[Sicklajoie]

Ken, I never get tired of looking at pics of your truck.
I've got 4.10s with 265/75/16 and get 12mpg on a good day. I just live with it.

[Alex V.]

Cool! Garden tractors and heavy Chevys are common interests of mine, too. While a little different animal, I have 4.10's in my '85 1-ton. SRW, 454/TH400, and 235/85/16's. I've DD'd the truck for numerous stints over the past 9 years (and a little over 40,000 miles) and after mulling it over plenty of times I've concluded the only thing that would spur me to change out the gears is if I could foresee doing a lot of long distance (hence, mostly interstate) towing, yet not laden near the truck's load limit. Even then it would only be to 3.73's. My "cruising" speed is between 60 and 65, towing or not - that's just where the truck feels right. I'll run it up to 75 for short periods but especially with a load it starts telling me it's working pretty hard to sustain that. With anything more than 7,500 lb. total cargo weight I'm plenty glad I have 4.10's - I feel with 3.73's, on anything but fairly flat interstate, I'd be wanting to wake up the engine a bit to keep that much weight moving and have any torque to spare. IMHO 4.10's are the best all-purpose ratio for the 20 and 30 series trucks, but that's speaking purely in terms of work - not play or gently used classics that need a little improvement in highway manners. Either way, beautiful truck. And mine (bone stock, Q-jet, HD emissions [no catalytic converters]) can squeeze 12.5 MPG empty, pure highway, and it's hard to get less than 9-10. I can figure on 11 hauling something less than 3,000 lb. down the highway.

[special-K]

Where is this show??? I don't own a Wheel Horse but I really like them. Know a little but would like to learn more. My buddy is all about them and has the last year model he uses now. Has another, not so old one, too. The really early ones grab my fancy.

Road trips are awesome in these trucks. I couldn't imagine a trip without a road . Sorry, just wonder how the term became so widely used these days. You have the best combo available with the tall narrow 85 series tires. They are the closest equivalent to stock 7.50-16s, and are specifically truck tires. I traveled all over the country in my '71 Custom Camper with 33/12.50s rolling along at 70-75 mph. Yeah, a stopped for gas a good bit, but that's always been the case with owning trucks. I don't think a swap to 3.73 from 4.10 is worth it. I'd consider a 3.54 rear change, if anything. That's right about a half a turn less. Have you tried turning it off and drifting down hills?

[Ken B]

Alex you have convinced me to leave well enough alone with the rear gear ratio. I don't typically drive my truck as far as I did to this tractor show. I was in no hurry on the highway and I'm ok with 10 mpg. Sometimes ya just gotta sick back and enjoy the ride...
The Wheel Horse show is in Biglerville Pa. People come from many different states too spend 3 solid days of nothing but Wheel Horse and great company. A few pics for Special-K. I Hope know one minds...I have dwindled my collection down some but here are a few of my favorites. First up is a special edition 420 with lots of factory chrome and leather wrapped wheel and seat. This tractor sold new in 1986 for 8500.00 bucks. They only made 250 of them, and a pic of a few of my oldies...
Alex you have convinced me to leave well enough alone with the rear gear ratio. I don't typically drive my truck as far as I did to this tractor show. I was in no hurry on the highway and I'm ok with 10 mpg. Sometimes ya just gotta sick back and enjoy the ride...

[yuccales]

Truck & tractors are very cool!

[special-K]

Go red! I should have known about that show. I usually take the back roads home from Carlisle and one route takes me through Biglerville. a friend on mine's great grandfather was one who got that whole orchard thing going in that area.

[Ken B]

Originally Posted by special-K

Go red! I should have known about that show. I usually take the back roads home from Carlisle and one route takes me through Biglerville. a friend on mine's great grandfather was one who got that whole orchard thing going in that area.

If you can make it drop on by, its such a beautiful area. It will be easy to find me, just look for the campsite with the Big Orange Heavy Chevy! The Longhorn got a ton of interest from young, old, male and female. I really did appreciate all the interest and was gracious but man oh man, when you answer the same questions and tell the trucks story about 100 times over the course of 2 days it sure does get old! Lol!