4-6 speed, hydraulic operated shift, automatic transmissions that work with first gen 350

[1977C20Silverado]

My trucks got a th350 right now but in the future I want to swap the transmission and do a 4wd swap. What would be a good transmission to swap in it for better gas mileage and towing etc? Also paired with a good transfer case. Needs to be heavy duty for off road use. I’ve been thinking a 700r4 but if yall got any better suggestions let me know

 

[CountKrunk]

I have a th400 or possibly th475 and i asked more or less the same question and the 4L80e is apparently what these evolved to be. So that's what I'm going to down in the future.

 

[dragstews]

Granted the 700 R4 is a good tranny, but it has the same spline count as a TH 350 (27)

The 4L80 has the same spline count as the TH 400 and the output shaft O.D. is a 1/4" larger than the 700 R4 ..
Much more robust in that area and others as well ..

You must be registered for see images attach

 

[TotalyHucked]

A 700R4 or a non-computer controlled 4L60 (4L60E denotes electronic control) would be a good option. Or a 4L80 (again, without the E on the end) would be a stronger option. I believe they went electronic in 95/96-ish? I'm sure someone can chime in about that

 

[dragstews]

It's the same transmission as the 700-R4 - merely a name change. The 700-R4 torque converter lockup was controlled by the engine computer from the late 80s, but all 700-R4s can have the lockup controlled without a computer. They converted everything to 4L60E with full computer control in 1994.

All 4L80E (91 to end of run 2013) transmissions use electronic controls; typically from the Powertrain Control Module. Some vehicles have shift maps that are selectable by the driver based on usage, such as towing.

Stand alone controllers are available though the after/market ..

You must be registered for see images attach

The above Stand Alone is going to be put to use in this truck ..

You must be registered for see images attach

"Believe it or not" ... It's a 75 K15 ..

I just acquired a 2004 4L80/85 that came from a shop who had a wee bit of a problem with it ...
(Fell off the jack and busted the bell housing) Eek !!
It's a 4X4 trans ..

Looks to be in good shape with what can be seen ..
Going to get it on the tear down table and go though it.
If it's buildable, I'll hunt up a good case and build it to sell ..