4L80e compatibility question

[knucklesavers]

So my friends transmission in there 1991 5.7l 2500 4x4 went out, I got a 1995 7.4l 2500 4x4 and wanted to know if everything would work fine, I know mine is a 4l80e not sure if hers is a 4l60 or 4l80. I know the transmissions are interchangeable on the engines but unsure if there is wiring or controller changes between the years

 

[ak diesel driver]

If it's a 4l80 the short answer is no

 

[knucklesavers]

Explain plz.

 

[EWC]

Larger and longer trans . Wiring is also different . This is not a bolt in swap .

 

[Will L.]

Should be 60 not 80.
Rebuilding a transmission is less expensive than modifying a different one.
If you are swapping to a 4l80e because the engine is gonna be built for more power- does more towing, want higher rpm on the hiway-
Then it can be done. Buy a stand alone controller, last I saw was around $700.
Transfer case needs modified or swapped to the other one which then means drivelines get modified. Also crossmember & mount needs altered.
Make sure you put the correct torque converter in as well-

All in, if you can diy everything should cost about $1,500 plus the cost of trans.

60 is a desired unit for better mpg.

Even swapping same transmission but different by a year or two takes a few hundred bucks.

 

[knucklesavers]

Ya she changed her fluid and put 15 quarts in it because the parts store told her that's what it took and smoked her transmission, I have a 1995 2500 AT 4x4 that I wrecked and thought it might swap into her 1991 2500 AT 4x4, she doesn't have the money for a rebuild, i was giving her the transmission and work for favor owed, if she decides to scrap the truck maybe ill grab it and put my engine/trans/running gear ECT...

 

[THEFERMANATOR]

91-93 4l80e is slightly different from 94+ electrically, and 95-96 more changes, and then 97+ saw some more. I generally tell people to consider 91-93 to be a different trans from 94+ because of the valve body differences. If the 91 is 6 lug, it will have a 4l60/700r4 in it, if it is 8 lug it will be a 4l80e.