3 on the tree

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trucknorris78

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Barry
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1978
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C1500
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89Suburban

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I don't understand is the weakness of the 3OTT setup, is it the actual transmission or the shift linkage?
 

DoubleDingo

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I don't understand is the weakness of the 3OTT setup, is it the actual transmission or the shift linkage?
Transmission. They are okay behind lower power, but apparently break under high horses. If you don't ever let it get on its high horse it'll be fine. They did come in 3/4 ton trucks, so I guess they can be okay under pressure, but those weren't high horsepower trucks, and they came with 4.57 gears because of the 2.94 1st gear. The linkage can be a weak point, but if you're not trying to shift like it's a floor shifter it'll be fine. And the column needs to be lubed and the linkage set properly, otherwise you're hunting for gears.
 
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Ricko1966

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Frame off yes, restoration,no. Cool truck yes, great project,restomod,custom. But restore is by definition,return to its previous condition.Your truck was never like that,so can't restore something to a state its never been in . It would not win a show as a restored truck,I don't think it could even be entered as a restored vehicle. I've restored vehicles,worked at a restoration shop,had to search for NOS tar top batteries,have leather of the correct grain dyed to match original color to restore the seats,and believe it or not,your paint can be too good. Paint wasn't that good factory,so its not original paint. Your truck sounds cool and I'm sure it will be cool,but it's no more a restoration than grave digger is a restoration. These cars below are restorations, original,drive trains,wheels,upholstery radios,etc. Again your trucks going to be cool but not restored.
 

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Fat 454

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Bad points - used to drive 3 on the tree back in the day when they were "regular" transport. Used to be infuriating if not properly maintained - jamming between gears at an uphill intersection, requiring a quick ( and well rehearsed ) jump out of the vehicle, fishing around under the hood to re-set, and then jumpback in and off with minimum hold up to traffic stuck behind.
Good - excellent theft deterrent. Most kids these days cant even drive 4 on the floor, so this set-up is guaranteed to stop anyone driving off in the truck!
Have a factory column 3 speed on a 72 truck with a warm 350. Runs fine ( is well set up with no worn linkages ) in regular traffic, but wouldn't plan on racing it anywhere.
 

squaredeal91

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Bad points - used to drive 3 on the tree back in the day when they were "regular" transport. Used to be infuriating if not properly maintained - jamming between gears at an uphill intersection, requiring a quick ( and well rehearsed ) jump out of the vehicle, fishing around under the hood to re-set, and then jumpback in and off with minimum hold up to traffic stuck behind.
Good - excellent theft deterrent. Most kids these days cant even drive 4 on the floor, so this set-up is guaranteed to stop anyone driving off in the truck!
Have a factory column 3 speed on a 72 truck with a warm 350. Runs fine ( is well set up with no worn linkages ) in regular traffic, but wouldn't plan on racing it anywhere.
My 61 would get stuck in between and I'd have to reset it by hand. Definitely was infuriating lol, I think It only did it because it had lots of slop. Was going to fix it but ended up trading it off. I Miss that 235
 

MikeB

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I think all will agree that the M13's 1st gear was not designed to handle the torque of a 427. So you'd have to take it VERY easy or start off in 2nd gear. And even then, I'm not sure the trans would live very long.
 

Ricko1966

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I can tell you, the guy that bought my old '70 C10 (6cyl 3 OTT truck) put a hot 355 small block in it and kept the 3OTT. It's probably in the ~425hp 400tq range and he's busted the 3OTT several times over the past 5 years. Enough that he plans to put a Tremec TKO behind it. He, like you, enjoyed the odd/uniqueness of the 3OTT but it has finally become not fun anymore.

My advice, go ahead and get a real trans that can stand up to that engine. Cuz the 3OTT flat will not last.
He can get an mc1 3 speed out of a big block car late 60s early 70s. GM used several different 3 speeds over time,some more robust than others,a 3 speed behind an engine with a bunch of torque is a good runner,less shifts,pull first real deep hit second,trap in 2nd
 

Craig Nedrow

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Having come from a 47-54 first series chevy trucks, (got to get rid of a few I still have...) background, I lived with those for thirty years. Those trucks had the linkage right on the top of the steering column, with a little box that you could adjust if the dogs got out of alignment. It shifted fast. Here is your Trans:

The Dearborn M13 transmission is a manual transmission unit produced by General Motors’ Dearborn Transmission Division. It was used in various Pontiac and Chevrolet vehicles from the late 1960s to the early 1970s.
Key Features
  • 3-speed manual transmission
  • 10 x 27 spline count
  • Fully synchronized
  • Used in Pontiac vehicles, including GTO (1970-1973), and some Chevrolet cars.
This is a 27 spline, the yoke will not handle the torque, nor will the T5 or T56, I have both. I love to shift personally, but unless you have tons (yes tons) of cash, there really is no stock trans that will handle that power reliably. That leaves you with few reliable options, Aftermarket manual, or a 4l80e. Even the 4l80e would need a few parts to be reliable.
 
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trucknorris78

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1978
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C1500
Engine Size
427
Frame off yes, restoration,no. Cool truck yes, great project,restomod,custom. But restore is by definition,return to its previous condition.Your truck was never like that,so can't restore something to a state its never been in . It would not win a show as a restored truck,I don't think it could even be entered as a restored vehicle. I've restored vehicles,worked at a restoration shop,had to search for NOS tar top batteries,have leather of the correct grain dyed to match original color to restore the seats,and believe it or not,your paint can be too good. Paint wasn't that good factory,so its not original paint. Your truck sounds cool and I'm sure it will be cool,but it's no more a restoration than grave digger is a restoration. These cars below are restorations, original,drive trains,wheels,upholstery radios,etc. Again your trucks going to be cool but not restored.
Okay, so I was focused on the, "frame off" portion of your comment. The restoration part was not a factor to me. I am not sure I even mentioned the word restoration. I believe I simply said resto. So, thank you for publicly explaining what the word, "restoration" means like I am an idiot. I thought this thread was about 3 on the tree but, there's one in every crowd.
 

Ricko1966

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This is mostly to see what opinions are out there. I am doing a frame up resto on a 78 GMC c15. I already have a 427 pushing 555hp. I want to keep the 3 on the tree because, I'm weird, I guess. Dearborn, M13 seems to be the only valid option. I do not yet know what rear gears I am going to run yet but, I am going to fab a 4-link rear. I am not racing the truck but, I am definitely going to play.
I'm going to pay for asking this but, what do you all think?
Sorry if I misunderstood you, frame up resto ,I assumed you mean't restoration of a truck that clearly wasn't being restored. But there's one in every crowd
 

Ricko1966

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Having come from a 47-54 first series chevy trucks, (got to get rid of a few I still have...) background, I lived with those for thirty years. Those trucks had the linkage right on the top of the steering column, with a little box that you could adjust if the dogs got out of alignment. It shifted fast. Here is your Trans:

The Dearborn M13 transmission is a manual transmission unit produced by General Motors’ Dearborn Transmission Division. It was used in various Pontiac and Chevrolet vehicles from the late 1960s to the early 1970s.
Key Features
  • 3-speed manual transmission
  • 10 x 27 spline count
  • Fully synchronized
  • Used in Pontiac vehicles, including GTO (1970-1973), and some Chevrolet cars.
This is a 27 spline, the yoke will not handle the torque, nor will the T5 or T56, I have both. I love to shift personally, but unless you have tons (yes tons) of cash, there really is no stock trans that will handle that power reliably. That leaves you with few reliable options, Aftermarket manual, or a 4l80e. Even the 4l80e would need a few parts to be reliable.
Please double check me and correct me if I'm wrong,but
Weren't the Dearborn 3 speeds ford top loaders with a different tailshaft housing and input shaft, I had thought about the Dearborn 3 speed for his project because they are tough as nails. We're the ever available as a 3 on the tree though I assumed no. The m13s were MUNCIE so were the m1s so 3 on the tree would be easy.
I'd love to find a Dearborn 3 speed for my project Chevelle, rumor has it they are tougher than the m22s
 
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trucknorris78

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Barry
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1978
Truck Model
C1500
Engine Size
427
Even the Dearborn would not hold up for this project. I have tugged on a lot of threads and keep coming up with the same answers. I was considering the SM465 but that granny gear has me on the fence. This is not a 4x4. I could just run 2nd - 4th but can't make up my mind. It would definitely work! Th400 is easy to find and can easily be made to work for this build. An uncle suggested a 2 speed Powerglide but, I hear about them being grenades.
You see these awesome hot rods and see the shows but, until you're into one, you don't realize just what goes into it.
 

DoubleDingo

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Even the Dearborn would not hold up for this project. I have tugged on a lot of threads and keep coming up with the same answers. I was considering the SM465 but that granny gear has me on the fence. This is not a 4x4. I could just run 2nd - 4th but can't make up my mind. It would definitely work! Th400 is easy to find and can easily be made to work for this build. An uncle suggested a 2 speed Powerglide but, I hear about them being grenades.
You see these awesome hot rods and see the shows but, until you're into one, you don't realize just what goes into it.
You don't use granny gear unless you're working the truck. Otherwise it's just a 3 speed, a strong 3 speed that will handle the engine, and would be minimal swapping since you already have the three pedals, etc.
 

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