rebuild 700r4 or 4180e for my carb-350 sbc

[BlackThunder]

Time to make a decision - My 700r4 has no reverse.
I heard that while 700r4 were tough and long geared. The 4180 is more efficient and lasts longer. If forced to do rebuild/replace what would you do?
I know that you need a controller to measure throttle position sensor (tps) and other data. Would be worth it to get the more expensive 4180e w/ controler and tps.
Or stay with the current set up and rebuild the 700r4.

 

[Vbb199]

The 4L80e* can be ran off of toggle switches to shift. Doesn't need Tons of bs to operate (earlier like, pre 99)

I think a user asked you when you first made your welcome post what gear ratios were in the axles ?
Perhaps you answered, but I have no idea.


If you're gonna build another 700r4, you should probably at least be at 4.56 based on the visible tire size you're running


The 80, if you run it, lacks the nice, low 3.08 first that the 700r4 has.
The 4L80e is 2.48 first, meaning, you'll need some pretty good deep gears ti get the rig going so you aren't roasting low/Rev constantly just to move.


Things to consider, but I recommend the 80. It's superior to the 700r4 in strength

For simplicity sake tho, the 700r4 only requires 3 wires and a TV cable to run.

 

[Matt69olds]

It depends on what your future plans are.

Do you have plans for major engine upgrades? You can build a 700 to take some abuse, but the major upgrades are expensive.

Big tires? Do you plan to beat on the truck? Once again, a built 700 will whimper at power levels and abuse that a 4L80 can handle with ease.

The loss of the deep first gear of the700 will be pretty noticeable. The 4L80 is bigger and heavier, so theoretically it will take more power to operate. I seriously doubt you would notice it by the “butt-O-meter, other than the first gear ratio difference.

If you are happy with the truck as is, get the 700 rebuilt with some cheap internal upgrades. Properly rebuilt, it will last as longer (probably longer) than the original.

If you plan some big power/tire/ upgrades or plan to abuse the truck, bite the bullet and go 4L80.

 

[BlackThunder]

Thanks for the reply..

The 4L80e* can be ran off of toggle switches to shift. Doesn't need Tons of bs to operate (earlier like, pre 99)

I think a user asked you when you first made your welcome post what gear ratios were in the axles ?
Perhaps you answered, but I have no idea.


If you're gonna build another 700r4, you should probably at least be at 4.56 based on the visible tire size you're running


The 80, if you run it, lacks the nice, low 3.08 first that the 700r4 has.
The 4L80e is 2.48 first, meaning, you'll need some pretty good deep gears ti get the rig going so you aren't roasting low/Rev constantly just to move.


Things to consider, but I recommend the 80. It's superior to the 700r4 in strength

For simplicity sake tho, the 700r4 only requires 3 wires and a TV cable to run.

Thanks for the reply, the gear ratios are a mystery to me until the diffs are open, if I'm right? All I know is I have a 14bolt in back and 10bolt in front.
The 1st gear is Bad-A!!! Not sure if I could ever do with out. Where would you buy your rebuild kit for a 700r4. I kinda like the simplicity aspect of the 700r4 as well.

 

[Vbb199]

I believe there's a Dana 60 up front and a 14 bolt ff in the back, it's highly probable if someone was meticulous enough to do the rest if the setup right, id be inclined to think surely it doesn't have 3.73 gears in it


How tall are those tires.


Also, I buy all my rebuild components from a transmission parts store.

 

[Catbox]

Here is the crazy super cheap way to run a 4L80.
CHEAPS is the story with this video.

@Bextreme04 can lead you down the road of how to control it with a stock GM 0411 computer from the junkyard.
That is the way that I will be controlling mine I hope.
If not, I will bite the bullet and buy the fancy controller as I know that works too.

 

[Bextreme04]

Harness and ECU from a junkyard is $50. You could probably get them from the same junkyard that you get the 4L80 from. You can probably get away with not even rebuilding the 4L80... lots of guys go years with a straight from the junkyard 4l80 behind high horsepower engines with no issues. If you got the wiring harness and ECU from the same rig that the donor 4L80e came from, you wouldn't even need to reprogram it if you didn't want to. But there is free software available and a tool to do the programming is only about $50. So $100 all-in for ECU, wiring harness, tool, and programming ability. The big cost is going to be converting your current transfer case to accept a 32 spline input from the 4L80E(your current 700R4 will be 27 spline), and getting new driveshafts or having your current ones modified. The 4L80 is several inches longer than the 700R4, so none of the driveline lengths will work with the swap.

 

[Vbb199]

They say a stock TH400 is about good for 400-500hp as is.

That's the story,

THAT SAID, it's modern, updated, big brother the 4L80e probably would do better in OEM form

 

[Bextreme04]

They say a stock TH400 is about good for 400-500hp as is.

That's the story,

THAT SAID, it's modern, updated, big brother the 4L80e probably would do better in OEM form

The generally accepted numbers for a 4l80e are that it will hold ~500hp all day long with no mods in a truck. It will hold more in light weight applications. The limiting factor there is the direct clutches(3rd gear). Basic, simple, and cheap mods to do on a junkyard trans would be to do an internal dual feed of the direct clutches, Superior shift kit, and either drill the pump for line to lube or use the Sonnex drilled PR valve for the same purpose. You can then drill the valve body plate for desired shift feel and it should hold around 500-700hp with no issues.

When you start getting above 700hp, you need to start getting into the big dollar stuff like billet input shafts, rollerizing the entire assembly, billet direct drum, etc...

Doing a basic teardown, cleanup, and simple mods on a junkyard trans would probably only cost you ~$300 in parts. A full Stage 2 rebuild kit from Jakes that is rated up to 750hp runs about $1100

https://shop.jakesperformance.com/shop/ols/products/4l80-rebuild-kit-stage-2

 

[BlackThunder]

I believe there's a Dana 60 up front and a 14 bolt ff in the back, it's highly probable if someone was meticulous enough to do the rest if the setup right, id be inclined to think surely it doesn't have 3.73 gears in it


How tall are those tires.


Also, I buy all my rebuild components from a transmission parts store.

The tires are 37''

Ive been going through and cleaning everything it looks like the 700r4 trans I have was rebuilt (paint and silicone). there was a pin wire disconnected on the side (I'm guessing its the reverse light only.) I plan to drop the fluid/pan. Hoping to find its the booster valve at the pump or something simple like disconnected at the internal linkage.
It feels like nothing shifting through Neutral and Reverse. No slip, No clunk, Nothing... Wish me luck

 

[Matt69olds]

The electrical connector is for the converter clutch. It has no effect of shift characteristics other than the lockup converter.

If it won’t move at all, most likely something happened with the pump, or the input shaft is torn out of the input housing. Usually the shrapnel from the pump can be found in the pan. If the input housing cracks where the shaft is pressed on, it will probably take a autopsy to find it.

 

[Rusty Nail]

Turbo 350 for the win.

 

[Rusty Nail]

Everybody needs Overdrive with 37s, right?

 

[Ricko1966]

Turbo 350 for the win.

Th350 is a real good compromise cheap,easy pretty tough,mods are easy biggest downfall is going to be losing your deep 1st gear.

 

[MtBraun]

I am pursuing a similar setup with matching a 4l80e to np241c. Build will be about 700hp so I'm not sure there are any cheap options, lol. Regarding the gear question, though, if I'm running 35" tires and 4.10 gears, if that steep enough to overcome the downside to 4l80e's 1st gear?