Ascender 6L90-E swap
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Joined: Jan 2014
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04 Ascender(trailblazer) currently a 5.3L 4L60e but it leaks so I was going to upgrade to an lq4/9 with a 6speed. Might listen to suggestions for an easier swap. I'm just trying to get better mpg.
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
I don't have personal experience, but from reading many trans thread here...
Your '04 PCM will not control a 6L80E; you would therefore need a special controller which costs $800. You would need to mod the trans mounting and get a shorter drive shaft. This assumes the large 6L80E even fits in your tunnel. Its extra 100 lb weight will not help your gas mileage. Also its 6th gear ratio (0.65) is not significantly taller than a 4L60E (0.70) and therefore unlikely to give you better gas mileage.
Just my opinion.
Your '04 PCM will not control a 6L80E; you would therefore need a special controller which costs $800. You would need to mod the trans mounting and get a shorter drive shaft. This assumes the large 6L80E even fits in your tunnel. Its extra 100 lb weight will not help your gas mileage. Also its 6th gear ratio (0.65) is not significantly taller than a 4L60E (0.70) and therefore unlikely to give you better gas mileage.
Just my opinion.
Teching In
Joined: Oct 2012
Posts: 13
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6L90 swap I put a 2011 6.0 litre with a 6L80 into a 41 Chev. It was quite expensive. The 6L90 has a huge output shaft and yoke. You need a motor that has a 58 tooth reluctor and a PCM that runs a 6L80 or 6L90. I paid $2500 for the motor, $1700 for the trans, and $2000 to have Speartech provide a tuned PCM, a wiring harness, and to retune the trans module. Speartech did a great job, everything runs well. For the same cost you could use a 4L80 with a Gearvendors overdrive.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
I put a 2011 6.0 litre with a 6L80 into a 41 Chev. It was quite expensive. The 6L90 has a huge output shaft and yoke. You need a motor that has a 58 tooth reluctor and a PCM that runs a 6L80 or 6L90. I paid $2500 for the motor, $1700 for the trans, and $2000 to have Speartech provide a tuned PCM, a wiring harness, and to retune the trans module. Speartech did a great job, everything runs well. For the same cost you could use a 4L80 with a Gearvendors overdrive.
On The Tree
Joined: Aug 2010
Posts: 122
Likes: 1
Agreed there is very little info on these types swaps. That should change in the near future. I have done quite a few of them, more to come.
