47-59 4l80 v 700r4

[mikeyptv]

Hey all! I'm mid-planning on my 57 Panel motor swap from 235 to sbc, stock suspension and steering. I'm debating transmission and wondering who has exprience installing either a 200-4r, 700-r4, or 4l80. My biggest concern is size / fitment. I don't want to have to do any tunnel mods.

Anybody have any experience or recommdations on fitment. I'd like to retain factory motor position.

Thanks!

[Rickysnickers]

I think the 4L80 is out then. I read where it's big and requires tunnel mods to make fit. Some of the more knowledgeable members will be able to confirm or deny this. Depending on your power level that you are aiming for, a 700r4, 4L60, or a 4L60e should work nicely.

[_Ogre]

Task force trucks don't have a tunnel. I have a 700R4 in my 58 TRUK, I did have to modify the trans cover very slightly. Probably caused by not having the cover on when I hung the motor.

[unclebrad]

I have a 700r4 in my 55, behind a BBC with no tunnel/firewall mods. Front suspension upgraded with Heidts Mustang 2 kit but engine mounts stayed where they were..

[mr48chev]

I'm going to have to quit reading these things late at night.

If you are using engine and trans out of a donor rig (s) I'd suggest using an engine and trans that came out of the same donor and have the computer to match as part of the deal.

200R4 is good for a mild engine and light duty. 700R4 you can tow with and run more power with without special internals. Both don't need all of the computer controls that a 4L60e or 4l80e do. The E standing for electronic controlled.

I don't think you will have as many issues in a 57 truck or panel transmission clearance wise as you would in an AD.

My preference is having the crank and main shaft centerline of the New engine and trans on exactly the same line as the original engine and trans to the point of taking measurements before I pull the original engine and trans and set the replacements in place. Meaning that if you lay a straight edge across the frame rails with it right in front of the end of the crank and measure how far the center of the crank is up or down from that straight edge your replacement should match that measurement. I haven't seen it in TF trucks but have seen AD guys mount small blocks several inches too high and build big tunnels simply because they wanted the engine to show when you stood back fifteen feet.

[Hcb3200]

I even have a LS 6.0 with a 6L90 in the 56 with no tunnel or firewall or trans cover modifications.
So based on the replies you have gotten i say pick one and go with it.
draw out of a hat>

[Stepside Jim]

_Ogre, is right, the floor is pretty well flat so the sides of the transmission is no problem to get to.

Years ago I used a Th350, the only thing I did to help the fit was made a small indent in the removeable floor cover where the top of the trans case passed by the lower edge of the firewall. it wasn't necessary for fit so much as it made it easier to remove both the engine and transmission as one unit.

I just switched from the Th350 to a 4l80e. The 4l80e is longer but it didn't need any floor work to fit it in.

We do have a difference and that is I have a Camaro clip vs your original frame up front.

[unclebrad]

Great point!

[PDW HOTRODS]

It also depends on what you have for frame up front. Camaro subframe may require the engine be mounted a little higher than stock frame. If so then the small hump in the trans cover will hit the bell housing area of the trans. Keeping the engine low and not set back it should clear.

[bowt1ed]

My 57 has a SBC and 700R4 with a 2nd Gen Camaro subframe - no clearance issues at all.

Cheers, Jim

[Dan in Pasadena]

My '55.2 has a 6.0 LS with 4l85e and all we did was switch to the humped trans cover that came on that truck with 4 speed granny low trans from the original 3 speed. Fit fine.

Oh PS: Stock frame but Flat Out Engineering's crossmember for Corvette IFS

[dsraven]

hey Dan, do you have bugs stuck to your grille yet?

[Rickysnickers]

Originally Posted by dsraven

hey Dan, do you have bugs stuck to your grille yet?

Seriously Dennis, what do you think is the answer to that question?????? LOL

[dsraven]

They would have a hard time sticking to all the shiny stuff?
Haha

[fauXGT]

A 4L60E is the same as a later 700R4, but electronically controlled rather than a TV cable for the 700R. The early 4L60 were identical size wise (94 to 97, or something) to the 700R. Then they went to the 4L65 electronically controlled... and the rest runs on Windows 98.... or something like that.
Pretty sad that even the 'smart TV's' run on Android or whatever. I Can't remember how many times I've had to reset or power down the TV to reset it....just to watch TV.

sad.

[fauXGT]

I do have to add that my transmission guy told me that all the mounting points and outer dimensions and such for any 700R are identical. 88 and up have stronger internal parts which cannot be added to the 83-87 cases. I went to the junk yard for a solid 88+ case so he could build it to replace the 84 I had. 83-87 had weakened internal components that wouldn't hold up to much.

[01spirit750]

I have a 4L80 in my 57. I swapped out the TH400. The 4L80 is longer so a new rear crossmember will be needed.
There were no issues with the firewall or clearance.
Note I have a chevelle subframe so my engine location is a bit forward from stock.

Were about in CA are you located.

[mr48chev]

4l 80 os a larger physically transmisison .

Size aside, it boils down to the simple fact of do you want to deal with a transmisson that you hook up a TV cable (simple but very critical adjustment) and a vacuum line or do you want to deal with newer electonic controlled unit that you will have to buy a controll unit for ? That is anywhere between 270 and 7 something depending on who you buy from and how deep your pockets are. And don't listen to the spit and whittle club idiots who say that you can convert it to manual shift.

The electronic transmissions are great if you buy the engine and trans as a unit and get all of the control pieces. The trans by it's self is going to be a challenge to put behind an older carbureted engine with a plug a pre computer HEI.

The one issue with this bunch is that all too often when someone asks a simple question guys get way off base and aren't thinking the actual question though and giving the best answer.

Yes there may need to be a slight lower firewall or transmission hump mod but those usually aren't a big challenge unless you just flat can't fabricate.

[1project2many]

The factory automatic transmission in 55-59 was a big unit.


The rear engine mounts are actually bolted to the bellhousing leaving the transmission hanging off the back with no support. The bellhousing was shorter than the transmissions typically used with SBC which could result in some modifications to the tunnel. I think that you could use a four speed cover plate if you hd clearance issues with a newer transmission.

Electronic transmissions like the 4L80E require some type of controller. The controllers typically want data that has to be provided by various sensors. These sensors would need to be added to an older carbureted engine. The E series transmissions usually use an electronic speed sensor and do not have a way to drive a speedometer cable. If you are comfortable adding the electronics then an E series transmission could be the right way to go.

The 4L80E is a strong transmission. And it's heavy. Very heavy.


The larger mass of rotating parts will drain some engine acceleration. But the gear ratios are relatively tame and the added OD would allow a numerically higher final drive without spinning the engine too fast on the highway.2.48, 1.48, 1.0, .75. There are different versions so you should do some research before purchasing a used one.



The 4L60E is a lighter duty transmission than the 4L80E. It was used in millions of vehicles.



Chevrolet spent millions designing this transmission and millions more trying to make it live a long, happy life. Hydramatic was given the job of fixing it after Chevrolet and they have spent millions more. As a result there are a lot of differences between different year transmissions. A lot! GM used to have a mini-booklet detailing the differences. A good general rule with these is to stick with late '90s units for SBC. The gear ratios between first and second are a bit wide which can lead to the 1-2 shift happening very soon after taking off from a stop. Sometimes the shift happens at a weird place in the torque curve. Most people don't notice an issue though. Forward gear ratios are 3.06,1.63, 1.00, .7 . There is an aftermarket gearset that offers a narrow split between 1-2: 2.84, 1.55, 1.00, .7 . The nice thing is that this transmission is close to the THM350 in size and weight. It's significantly smaller than the 4L80E.

700R4 is an earlier, mechanical version of the 4L60E. Just like the 4L60E transmissions, there have been a bunch of modifications to the 700R4 over the years. Many of these transmissions have failed unexpectedly but these days folks can and do build 700R4 transmissions that are tough enough to last for years. 700R4 needs a cable connection to the throttle linkage and most of 'em had a mechanical speedometer cable. The lockup feature of the torque converter clutch should be used to help keep the transmssion cool on the highway. I would look for a late '80s to early '90s version of this transmission as a starting point if I wanted to use a 700R4. The gear ratios are the same as the stock 4L60E. I am unsure if the aftermarket gearset mentioned previously will fit the 700R4.

2004R is an overdrive built by Hydramatic Transmission.

I felt it was more durable than the 700 "back in the day" but there were still plenty of failures. Like the 700, the 2004R can be built to be very durable these days. The gear ratios are more street friendly: 2.74, 1.57, 1.00, .67. This transmission is actually slightly shorter than the 700R4. Some 2004R transmissions are designed to only bolt to Buick / Oldsmobile / Pontiac engines.

The reality is that the 700R4 is one of the most common transmission swaps these days and there are a bunch of aftermarket bits to support installing one into an older vehicle. Plus, 700R4 transmissions are fairly easy to find used. If you want to use a transmission that isn't a 700R4 be prepared to do some additional work along the way.