fakky

Transmission going into a 57 chevy truck.

1) which trans can accommodate 400 rwhp best ..... assuming both can when built right ..... which way would you go

2) how do I know if it will fit. Don't want to buy a 4l80e to find out won't fit without major sheet metal work

Thx

kinglt-1

iTrader: (26)

4L60's have been 8's in the 1/4 when built right. A stock low mileage 4L60 can handle 400whp all day long as it is tuned right with a shift kit and cooler.

LS6427

iTrader: (2)

Junkyard 4L80E with a fresh rebuild will be stronger, more reliable and last MUCH longer......and be WAY cheaper than a 4L60E.

Its a no brainer.

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98CayenneT/A

4l60e will easily hold 400 whp and will eat MUCH less hp than the 4l80e

LS6427

iTrader: (2)

Its hardly noticeable, especially in a heavy 57 truck. Id rather give up a tiny bit of HP to have a tranny thats literally 10 times better than a 4L60E. And again.....cheaper by far and better.

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clinebarger

I build both, And each has it's place.

A 4L80E has about the same footprint as a 300mm 4L60E, If one requires floor board mods....So will the other.

4L80E's do not "rob" as much power as people think, What people really notice after a swap is the gear ratio differences.

4L60E's put up with more power in lighter vehicles, It might hold 400rwhp in a F-body, But put the same unit in a Crew Cab Pick-up with 400rwhp.......Not so much!

It also boils down too how abusive are you going to be??? Give me 400rwhp & I can burn down ANYONE'S 4L60E inside of a month. Repetitive WOT Detent/Forced Downshifts kill 3-4 Clutches. The non-synchronous application and release of the 2-4 Band & 3-4 Clutch is the biggest pitfall of the 4L60E & it's derivatives.

4L80E's shift "Straight Through", No releasing of one holding member & the application of another to complete a shift.

The 4L80E has about twice the Friction Area, No dual purpose clutch like the 3-4's in a 60E.

A '57 pick-up isn't all that heavy, A well built 4L60E will probably serve you well, But a 4L80E will leave a lot of room to grow power wise.

fakky

Main concern is the fitment within the transmission tunnel. I now its bigger - but I also read some guys have had better luck with the 80 due to servo/exterior clearances.

fakky

Interesting. I've not heard of a straight through shift ...... My old truck had a built 47re/a618 ........ pretty sure that shifted the asynchronous way you mention with holding the 2-4 wil shifting ....... and that was 700hp/1200 torque. But different trans.

So from a tuneel clearance perspective - the 60/80 are similar ?

Sounds like everyone is saying the 80. ...... cant remember if there is anything different electronically apart from a reflash to program as a 80.

I know some guys were not liking the 80- due to that 1st gear gearing at transmission.

So ..... if going with the 4l80e ...... what rear end (and ratio) to match best gearing for daily/street

thanks guys

wht/73

Yeah you might notice a diff going from 3.06 to 2.48 1st gear.
I'll be going from 2.52 to 2.48.
Probably not even noticeable.
2nd gear 1.63 to 1.48 for you.
For me 1.52 to 1.48.
A wash.
It will make my 4.30's stretch a little longer!

clinebarger

Yep, On Dodge A727 based units The Intermediate Band has to come off & the Directs have to apply on a 2-3 shift.....Same deal on a 700R4 based unit, The 2-4 Band has to come off & the 3-4 apply for a 2-3 shift. The thing is......The Direct Clutch on a A727 is more robust than the 3-4 Clutch on a 4L60E.

The 4L80E shift straight through...

Forwards applied....1st gear
Forwards/Intermediates applied....2nd gear
Forwards/Intermediates/Directs applied....3rd gear
Forwards/Intermediates/Directs/4th Clutch....Overdrive

The Intermediate Sprag is what makes it possible to have a 2-3 shift without disengaging the Intermediate Clutch. The Sprag overruns on the Direct Drum in 3rd. Even though the Intermediates are applied their not holding anything in 3rd. TH400 & TH350 are the same.

fakky

3.06 being the 727 you mean ?
If I go with a 4l80e ..... assuming I will probably want something like 4.10s in the rear to help with the trans ?

fakky

Thanks. That's interesting.

1) if you were doing this swap ..... would it be the 4l80e you would put in...... or something else ...... manual is also an option ..... it has a t5 now with straight 6bengine .... but as a daily was leaning auto.

2) Does the 4l80e need anything different for swap into truck. The 4l60e I think just needs a flash if not original to engine ..... not sure about 80. Assuming same but thought I remember reading of a other issue.

Thanks guys

wht/73

No the 3,06 is the 60e

fakky

Gothcya.

So best gearing in rear would be something with a high ratio like 4.10s...... versus says 3.53 ....... if I go the 80e route

clinebarger

Need more info on your build, What engine/mods? A high strung 5.3L vs a Torquey 6.2L is a big difference.

A 4L60E PCM will need a 4L80E "Segment" installed. PCM's with a 4L80E segment are dirt cheap. This small detail shouldn't effect your decision.

fakky

Ad of right now probably a truck 6.0. Looking for 400 rwhp. Daily street. Reliable and fun.

I assume if I go that route with say an lq9 with original 4l80e not required segment swap. And if I don't ......say I go 5.3 ..... then it's simply a programming fee to hptuners etc

LS6427

iTrader: (2)

Listen to "clinebarger".....he helped me out with all the exact info, that I could not find anywhere else.

Like we both said above....don't listen to the "4L80E will rob a lot of power"...its just not true. It robs almost nothing and you will not feel the difference.

The thing people don't think of is....the weight that the little weak 4L60E has to get moving. A big truck is a lot of weight to throw at the 4L60E. Its not just a HP issue. My built 4L60E behind the 427ci I had, was 500 RWHP/500 RWTQ. But I was always on street radials, NEVER a drag radial at a drag track doing hard launches with good traction. So my tires just spun on the street as compared to hooking under load at a drag track....much less stress on the street with radials. If I was drag racing it, it would have simply broken into pieces behind 500 RWTQ.

FITMENT:
If a 4L60E will fit...so will the 4L80E. Especially in a big vehicle like you have.......

"clinebarger" can give you technical info.....I just know there's absolutely no reason to buy a 4L60E when you can get a 4L80E cheaper.....and have a tranny thats 10 times better in every single way. There's not a single negative.

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LS6427

iTrader: (2)

fakky:

Yup...thats what I did. 98 PCM.

Just call/online-order from Frost and buy their plug-n-play harness. Then for $25.00 you send him your PCM and he reprograms it so it works perfectly with your 98 PCM, and sends it back....3 days.

Hook it up and you're DONE.

http://www.tunedbyfrost.com/products_dev1.htm

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fakky

Thanks guys - you've been super helpful.

If I "DO" need to modify the tunnel ......... hard ?
Not the best welder ........ but figure I can and will have to learn
Anything structural I would tack in and have a pro do it on a mobile unit.
BUt a tunnel and sheet metal figure I can cut and tack until happy.


What gearing would you guys go with on rear .... ???

98CayenneT/A

If you were to run the quarter mile in a stock ls1 with a 4l60e then swap to a 4l80e you absolutely will run slower times with the 80e