4l60e or non 'e' best transmission for rebuilt 350?

[desert-rat]

I have a rebuilt 350 with a 4 bbl in my '72 C10. Currently has a turbo 400. Not the best highway transmission in my opinion. The truck is just a cruiser. No heavy hauling or racing. But do want an automatic transmission that'll handle WOT and has overdrive.
Will the 4l60e or 4l60 be best or what else do you recommend?

[weq92f]

Originally Posted by desert-rat

I have a rebuilt 350 with a 4 bbl in my '72 C10. Currently has a turbo 400. Not the best highway transmission in my opinion. The truck is just a cruiser. No heavy hauling or racing. But do want an automatic transmission that'll handle WOT and has overdrive.
Will the 4l60e or 4l60 be best or what else do you recommend?

.

It's not but with the right rear gear a nice compromise can be dialed up. The 400 is strong and reliable. If you put 3.08 in the rear, it would be much better on the highway around 70mph would be right at comfortable I'd say. Off the line, it'll do OK depending on your 350. Perfect for a cruiser.

If you want to have great performance off the line and low RPM highway speeds, you're gonna need that OD tranny or an OD unit hanging off the back of your 400. My buddy drives a 350/350/3.08 and keeps up with me all the way up to just over 80 fairly comfortably. Over 70 or so for short bursts only...it's a cruiser. My 700r4 w/3.73 in the rear is a very fun combo with my setup (Torquey 396). It will hammer good from a stop and cruise comfortably at 90 all day long.

For the money and effort I'd try the rear gear first. Maybe source a rear end with that gear and swap it for a test.

-Kevin

[Accelo]

The newer the transmission the lower 1st gear.
Everything being equal acceleration in first will be improved.
I always recommend a 1987 to 1992 4L60E as one also gets a 30% reduction in cruising RPM.
A much quieter cab is an additional benefit.
It will handle athe 350’s HP with ease.

[Bob B.]

A 4L60E is a 4L60, also known as a 'Turbo 700' (700R4), with electronic controls. Gear ratios are the same. A 4L60E will need a transmission control module and various sensors to shift properly, but aftermarket kits are available. The 4L60E also uses an electronic speedometer. The 4L60E came out in 1993. The Turbo 700/4L60 use a vacuum modulator and a kickdown cable to control shifting, so it's easier and less expensive to install in an older vehicle. The 700/4L60 also uses a mechanical speedometer, so that's no issue.

[1970cstblazer]

I believe that the 1982-92 700R4 only uses a TV cable for it's shifting purposes, and no vacuum inputs.

[cj847]

Assuming your budget has some kind of limit I would go 700R4.

With an E transmission there is a ton of expense. The transmission controller alone is over $700. Then I think you also have to have a throttle position sensor added etc. Wait until you do an LS swap and get all that for free.

I cannot quote the exact years but the early (1984-86?) 700R4 is said to be weak, but by now most have been rebuilt with later year internals. At some point the speedometer was changed to electronic but is easy to convert to mechanical with a <$100 kit. Make sure whoever installs it knows how to adjust the TV cable.

[Rickysnickers]

Originally Posted by 1970cstblazer

I believe that the 1982-92 700R4 only uses a TV cable for it's shifting purposes, and no vacuum inputs.

This is how my 700r4 is set up. Mine has no vacuum hook ups.

[dagnabbitt]

My 700R4 is a 1991, I think you want 87-92 for the best internals and highest number of splines, etc. It is certainly a difference maker if you drive the highway a lot like I do. I use a GPS Speedo.

Some people like the 200-4R as well. It depends upon your budget. if you are going for new - or rebuilt with better than new parts - then they are both great transmissions.

There's nothing tougher than a TH400, though. If you are generally happy with your truck and just want lower rpms, then before you swap transmissions and rear diffs you might check out Gear Vendors for about the same money.

[Bob B.]

Originally Posted by 1970cstblazer

I believe that the 1982-92 700R4 only uses a TV cable for it's shifting purposes, and no vacuum inputs.

You are right, confused it with the TH350.

[Already Gone]

My truck with the original 350/350 had 3:73's from factory out back. In 2019 I had a newly rebuilt 700R4 installed and was great upgrade. In 2023 a properly built small block 400 was installed in the truck. Nothing exotic just wanted a reliable ressponsive truck. If you dont want to race the truck and want a reliable driver I think a 700R$ with 3:73's out back with your 350 engine is the way to go.

[pjmoreland]

Originally Posted by Bob B.

You are right, confused it with the TH350.

The early stock 700R4 configuration used a vacuum-controlled relay to lock/unlock the torque converter clutch based on throttle demand/manifold vacuum level.

[tim_mc]

Originally Posted by pjmoreland

The early stock 700R4 configuration used a vacuum-controlled relay to lock/unlock the torque converter clutch based on throttle demand/manifold vacuum level.

Yep - I had my '92 700R4 built with a hydraulic lock-up kit that didn't require an electric solenoid. Here's a Transgo kit for reference:

https://transgo.com/product-details/...aulic-lock-up/

[weq92f]

Originally Posted by pjmoreland

The early stock 700R4 configuration used a vacuum-controlled relay to lock/unlock the torque converter clutch based on throttle demand/manifold vacuum level.

.

My 700 is 1988 vintage. It's electronic lockup control is too rigid as installed. I would welcome a vacuum (or lack of) switch to unlock the thing under heavy throttle input. As it is, if I want that functionality, I've got to add a vacuum switch and some logic to make it happen...or lightly hold the brake switch with the pedal while I hammer the throttle!!!

So rather than that, I just live with the fact that when it shifts to 4th, it will lock and stay locked until I hit the brakes, shift to 3rd or hammer the throttle hard...and wait a half second.

Still a blast to drive...

-Kevin

[Accelo]

Some owners install the 4L60 without connecting the Lock-Up. It will function fine, but you will not get the last 200-RPM reduction.
The later model 4L60E's can not easily be converted back to an analog speedometer. (They have 6 bolts holding the tail shaft versus the earlier ones with just 4 bolts).
The 4 bolt, tail shafts, can have the earlier analog tail shaft installed in place of the electronic ones.

All this is dealt with when using the factory computer and the 4L60E. They can include PWM lockup of the converter or just the (on-off). You can also set the shift speed electronically. They will also increase line pressure with a trailer or even if the computer high throttle application. It's like having a shift kit and then reverting when you no longer want to play. In some cases, they also will retain your speed going downhill by applying the converter clutch as required. They come highly recommended if you are running an LS motor. They just work!