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2/3/10 6:30pm - Original Message: 'Transmission change for 81'
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Joined: 1/21/2006
Posts: 25
I have a 3.73 rear in my 81 and was thinking of changing the transmission to a 4 speed auto from a 82.  I wanted to know if this is just a bold in swap and if any other changes would have to be made.  I was thinking of this so that the RPMs would be less when crusing at highway speed.
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2/3/10 8:38pm - Reply: 'Transmission change for 81'
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Dutchess County, NY - USA

White '79 Corvette. It's a driver.

Joined: 8/27/2007
Posts: 2484

I believe you need to add a new torque converter, have the driveshaft shortened and install a new kickdown cable & hardware.

I hope to do this swap to my '79 this year or the next.

A few members here have done this swap with the 700R4 and the 2004R. I'm sure they'll weigh in soon enough.



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2/3/10 9:32pm - Reply: 'Transmission change for 81'
lukesvette Lifetime Member
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1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.

Joined: 5/18/2004
Posts: 6807
Starting my conversion this weekend hopefully. TH350 to a 700R4. In addition to what Kevin mentions, you need to check the placement of the crossmember and you'll need a modified shifter detent.

As a side note, if anyone is interested in a nicely built TH350 with a Trans Specialties 2800 stall converter, send me a PM. Good trans and you won't find a cheaper deal!!
LukesVette2010-02-03 18:32:39

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2/3/10 10:34pm - Reply: 'Transmission change for 81'
SilverStreak Lifetime Member
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Oceanside, CA - USA

1978 Silver Anniversary model. Original L82 engine, 700r4 trans, edelbrock intake, thorly headers, rack&pinion steering, mono rear and front spring, MSD 6A box

Joined: 11/19/2003
Posts: 191
When I changed my 78 from the TH350 to the 700r4 I had to do all that was said above and also move the E brake bracket over to clear the longer transmission. Belive me you will be glad you made the change.  You will realize a big improvement in your gas mileage.


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