The Stovebolt Site Forums The Shop Area Engine Shop horse pulling 72 3/4 4x4

my 72 has a healthy 350 that can't pull my trailer and two horses up MT mountains without downshifting. What should I be considering as an alternative; 383, 400 or 454?

Lower axle gear. Get a 4.11 gear set. New trucks have that for pulling. Or can get 3.73 for better mileage, less GVW though.

Thanks for the reply. Unfortunately the truck already has 4.10 gears.

Or you might want to step "down" to a 292 (?)

I would think that a good running 292 would be strong enough to move a load the weight you mentioned.

-ftyler

Bigger is better, if you can afford it. The 454 will do the work, just be sure you have enough tranny behind it. Dad had a 92 with 454/700r4 and 4.10 gears in his one ton, pulled a long trailer and a heavy load into the Idaho mountains on a regular basis. If you really want a puller, go with the Duramax!

Fred's right, but I was thinking "budget". I'm frugal that way - forgive me!

-ftyler

Does your 72 have a manual tranny or an automatic?

tranny is a 350 with a nice big oil cooler. What are some more thoughts on a 292.

a 292 six with rv cam and 4 brl carb would probobly have more low rpm hp

one thing you could do is put 4.56 gears in your axle and than add a after market overdrive

A healthy 350 will run away and hide from a 292 .With 4.10 gears your engine must be turning 2500- 3000 rpm at 60 ? At anything above 1000 rpm the 350 is stronger unless you have the V-8 all cammed up. Let the truck down shift, that's what the tranny is for.

Coupe,
Even my 1-ton dually with the 488 V10 downshifts going up a hill with the trailer and two horses -- Like Tony said, that's what the tranny is for. A buddy of mine who pulls a lot of hills told me that when the truck lugs down (he has a 3/4-ton with a utility body that he hauls a Bobcat with) really far and struggles, he shifts into 4WD. He claims that transferring the power from one axle to both helps spread the stress and makes it easier on the truck.

My truck has never been challeneged that much so I've never tried that myself, but it does make sense.


Just a thought...
Regards,
John

410 axle was provided stock for big block with automatic. Stock gears were 4.56. Still, the 410's save a lotta rpms when you don't need 'em. Just shift and make the best of it, or throw in a big block....

how big are them hills? the size of the engine is important but should get downshifting anyway. watch the big rigs on the hills, bet they downshift too.helps keep in power band.

Somewhere in this form,someone said that the third member from a 67-72 3/4 ton automatic will interchage with the third member out of a 1954 3800 chevy (5:14) What a great idea.

Tony'n Weatherford(Texas that is)

Forgot to aassk what size tires you got. I keep seeing these lift kits and 38 inch tires around here. They will sure cut down your power on the hills!

Tire size is 235/85/R16. I measure about 31 inches diameter.

if your truck has stock rearend than its gear set will inter change whith 49-72 3/4 ton gear sets
the only thing difrent between a AD 3/4 axle
and 67-72 3/4 ton axle is thay have upside down spring perches and narrower brake drums

4.56 gears and would cut your top speed a littel
but give you ****** hill climbing power
But you could add a over drive and fix that

Regardless what you do with gears, there's no substitute for power :p ! For towing you cannot beat a diesel but a big block is the next best thing. Somebody puts out a 502 towing motor brand new for like $3500 or so. I put almost 3 in my 454 but I've got over 500 ft lbs from 2000 to 3500 rpm, can't beat it for towing. Besides, Big blocks cool alot better under that kind of load and will last longer than small blocks. I know, gears do make a difference, but I run 3.73's in the '76 with the NV4500's .73 OD and that gives me a nice ride at 80 mph. My dad had a '79 3/4 with a 350, turbo 400 and 4.10's and that thing got pretty old after about 30 min on I-25. My .02. :confused:

There is no replacement for displacement !!

A third member with a 4.57 gearset would be a lot cheaper (if I was closer, I could GIVE you one) and could easily be installed in an afternoon.........will throw off your speedo, though............

Coupe - I just had a bright idea! Y'all have this all wrong. Hook them horses to the trailer and have them pull the trailer up the mountain. Then, when it's time to go down the other side, let them ride again. Only good use I ever found for a horse trailer was to move the kids off to college.

And these guys are right. You'll burn up that SBC pulling a heavy trailer in the mountains.

I guess I'm going to be looking for a descent big block. Any suggestions on what to look for or how to make the change over. I really appreciate all the knowledgeable advice I've been getting.

I have ran the dog doo out of my 72 3/4 4X4 with a 350 and a TH350 auto for about 6 years now.I recently hauled an early 6X6(yes,3 drive axles, large transfer-case and large winch on the front)out to a buddy`s place 70 miles one way up a few steep hills.It will do fine as long as you can be patient and drive accordingly to the load you are hauling.Horses were not meant to move that fast anyway

I just put 2300 miles on a 31 foot long motor home with a fuel injected 454 w/4L80E transmission and 4.11 gears? (about 2100 rpm @ 60 mph), had no problem on the flat hitting 85 mph when passing.

I figure the rig weighed in at around 14000 lbs which should be a bit more than a 3/4 pickup + 2 horses in a trailer. Coming up Teton pass with a 10% grade, ran nice at about 30 mph in 2nd gear. Cut back to 5% grade and did 60 mph in 3rd running about 3000 rpm. Averaged about 10mpg for the whole trip and I did not drive it easy. Fuel injection and a 4 spd tranny is the way to go if you are looking for towing torque and economy.

Two years ago I met a guy who had taken the 350 out of his burb and put in a late model 454 with fuel injection. Claimed to be getting better fuel milage with the big block. If you go that route, get all the engine wiring and computer.

Will a 4L80E transmisson bolt up to my 350 turbo transfer case?

You may have a NP 203, 205 or a 207 (I think these are the right #'s) but you need to figure out which you have and then give the folks at Advanced Adapters a call and they can tell you what you need. Sorry I don't have their # but somebody here will or you can do a search for it.

I have a 72 Cad with a 472 engine sitting out back. How much harder than a 454 would that be to install in my 72 chev?

eldorado?

Check out this thread
472 caddy in a 71 3/4 chevy