4L80 or OK with 4L60

[Barnyard]

Planning and 6.0L LS swap for my 82 2WD and my son keeps telling me that I should go for a 4L80 tyranny for our project but I'm wondering if it is really critical for stock / light upgraded 6.0L LS and could stick with a 4L60?

 

[JoeR Jr]

There's no shortage of strong opinions on this subject. A search here will turn up more reading than you could get through in a weekend!
For my 2 cents I'll say for a daily driver, the 4L60E is a great trans and it will last a good, long time. If you're going to tow a lot, or beat on it at all, then invest in the 4L80.
Joe

 

[eskimomann209]

I’m also in that belief. There was a few cases where the 6.0 was partnered up with the 4l60e. I think these trucks are so light that you’re not going to break anything besides traction if you stomp on it.
I plan on putting a LS383 in my 73 here pretty soon. I’ll keep the 4l60 until it dies. Then probably swap to the 4l65 IF I need to.

 

[HotRodPC]

There's no shortage of strong opinions on this subject. A search here will turn up more reading than you could get through in a weekend!
For my 2 cents I'll say for a daily driver, the 4L60E is a great trans and it will last a good, long time. If you're going to tow a lot, or beat on it at all, then invest in the 4L80.
Joe

THIS !!!

 

[RoryH19]

I’m also in that belief. There was a few cases where the 6.0 was partnered up with the 4l60e. I think these trucks are so light that you’re not going to break anything besides traction if you stomp on it.
I plan on putting a LS383 in my 73 here pretty soon. I’ll keep the 4l60 until it dies. Then probably swap to the 4l65 IF I need to.

x2

 

[RoryH19]

My K5 has a LS 6.0 and 4L65e from an Escalade.
Same footprint as the 4L60e but stronger with the additional planetary (5 total).
4L80e's are typically for the 3/4 ton+ chassis. They are nice and strong but take up more space. If you are setup for a 4l60e I would keep it. Especially on a 1/2 2wd.
However if you find a donor 6.0 with a 4L80e already attached just drop that in.​

 

[C10MixMaster]

i would use the tranny from the same donor the 6.0 came from . that way the comp and harness already match.

 

[eskimomann209]

i would use the tranny from the same donor the 6.0 came from . that way the comp and harness already match.

Swapping the transmission plugs are easy

 

[HotRodPC]

Swapping the transmission plugs are easy

Yes, don't let the plug and wiring pins keep you from an upgrade if it's what you want. In fact, I've been told, it's just a matter of swapping 2 or 3 pins in the plug and that's all there is to that. We used to have a guy here that would repin the plugs and make it a turn key plug and play swap.

 

[Mark Vucelick]

I am running a high horsepower 2wd and am installing a 4l80e.

I still have bad memories about the old 700r4 being able to handle big power with the "right" parts. I bought a "guaranteed to 900hp" 700r4 and, even though i had half that power, broke it with astonishing ease in a k5 blazer.

If you are running a stock horse LS you may be ok. Any power added, or towing, or goofing off at the drag strip go with the 4l80e. No more or less expensive.

 

[Matt69olds]

I have built lots of both transmissions. You can bolt in every upgraded fancy part into a 4L60/65/70E transmission, it’s will still be weaker than a stock 4L80. In my opinion, other than premium friction material, a drive shell, and shift kit, if you need more than that for a 4L60 to be expected to live, then you need a 4L80. By the time you spend the money for all the fancy stuff, you could have bought the parts to install the 4L80, and not worry about breaking it.

The trouble with the 4L60, about the time you add enough friction and pressure for the clutches to not slip under load, you have exceeded the load capacity of the hard parts (shafts, gearsets, sprags, etc). The 4L60 was originally designed back in 1982 for use behind wheezing 305 and v6 engines. GM has continued to update and improve the trans, but it definitely has its limits.

 

[Barnyard]

I actually found a full donor truck that was running and driving great!. 6.0 with 4L80 and all harnesses. We are in the process of stripping the donor down now and saving all harnesses/modules until I figure out how to hook it all up to my SB.

 

[Marcoman]

I actually found a full donor truck that was running and driving great!. 6.0 with 4L80 and all harnesses. We are in the process of stripping the donor down now and saving all harnesses/modules until I figure out how to hook it all up to my SB.

Cool, any update on the new project?

 

[Barnyard]

Cool, any update on the new project?

Marcoman my build thread is here: https://www.gmsquarebody.com/thread...87-gmc-sierra-2wd-long-bed.28879/#post-566444