C6 trans and diff into c5
Thread Starter
Racer
Joined: Oct 2018
Posts: 458
Likes: 29
From: Bellingham, wa.
C6 trans and diff into c5
So I have a 98 auto c5. It has a 4l60e and 2.73 rear diff. I have a line on a great deal on low miles c6 auto 4l80e and 3.43 rear diff. What all would be needed to fit these into my c5. I remember seeing somewhere a guy did this and said to make the trans fit took a sledge to the tunnel to Clarence for the bigger trans. Also what about the trans hitting the pavement over speed bumps etc, also torque tube, changes there?. Any info would be appreciated
Acct Suspended APR 2026 by request
Joined: Dec 2010
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2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
... I know a bit about manual c6 swaps but don't know anything about c6 auto swaps, interested to hear what's involved
Drifting
Joined: Sep 2017
Posts: 1,961
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From: Avon Lake OH
First off the factory A4 in the 2005 C6 was a 4L65E. In 2006 the factory switched to the 6L80E automatic. Not sure where or how or if what you are looking at is truly a 4L80E transmission. Also unless you have 1000hp and are drag racing you C5 all the time, you really don't want to attempt the 4L80E swap or the for that matter the C6 6L80E swap either. You can call a shop that has done some of these conversions on C5 for more info like:
https://www.raceprovenmotorsports.net/
A nicely re-built 4L65E/4L70E and a rebuilt '01-04 3-rib C5 case with say a 3.42 gear and HD C6 Z06 internal components would be a much better, easier and way less expensive swap. Talk to someone like these guys;
https://www.rpmtransmissions.com/page27.html
https://www.raceprovenmotorsports.net/
A nicely re-built 4L65E/4L70E and a rebuilt '01-04 3-rib C5 case with say a 3.42 gear and HD C6 Z06 internal components would be a much better, easier and way less expensive swap. Talk to someone like these guys;
https://www.rpmtransmissions.com/page27.html
Last edited by JHrinsin; May 26, 2019 at 10:03 AM.
Thread Starter
Racer
Joined: Oct 2018
Posts: 458
Likes: 29
From: Bellingham, wa.
I am going drag racing and I want the extra strength with the 6l80e and diff combo, I had a4l60e built to level 5 with a rossler trans break and a zip built three rib 373 and broke pretty much every part during last summer. I am only at 500rwh but the hard launch using the trans break is pretty hard in the c5 stuff plus a few more gears might be fun. My bad before for posting the 4l80e
Last edited by Faster5; Dec 10, 2019 at 11:44 PM.
Team Owner
Joined: Oct 1999
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From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
If anyone has done it, it is RPM. I have never heard of a 6L80E swap in a C5, the challenge would be getting a computer to run the trans as the C5 electronics were not designed to run a 6 speed auto. RPM has done 4L80E conversions using a C6Z diff.
Last edited by 93Polo; Dec 11, 2019 at 10:54 AM.
