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Author Topic: trans swap  (Read 1258 times)

Offline 87454westernhauler

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trans swap
« on: February 02, 2012, 09:37:45 PM »
thinking about swaping the th400 in my 85 c20 350 sbc for a 700r4. if i can find an early one from a 85 or 86, that doesnt have all of the electrical sensors, how much stuff will i need to mudify like drive shaft or cross member?
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86 c10 350 sbc 700R4 Daily Driver
79 gmc c20 350 th350
78 k1500 4x4 350 th350

Offline bake74

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Re: trans swap
« Reply #1 on: February 03, 2012, 07:43:24 AM »
     I believe the cross member will have to be pushed back a little, the drive shaft will have to shortened a little also I believe the 700r4 is a little longer.  I could be wrong, I am sure someone will chime in.
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Offline Captkaos

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Re: trans swap
« Reply #2 on: February 06, 2012, 04:38:07 PM »
TH400 has a 27-15/16" distance from face to CL of the trans mounting.
700R4 has a 23" distance from face to CL of trans mount, on typical transmissions.

You would have to move the crossmember toward the motor for it to work.

Any 700R4 prior to 1987 I would avoid like the plague, they have several weak components which were not fixed until 1987, and you can use many newer components in them that you can't in the pre-87's. 

There are NO electrical sensors on 700R4's except possibly a VSS, and you can easily buy a cable setup for them as they were available from 1982-1989.  The only other connector is the converter lockup, and you want that.
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