remove 4+3 install 700r4

[macgyver]

I have a 1984 with a 700 in it and a 1985 with a 4+3 what do i have to do to put the auto in the 4+3 car?:W

 

[philbillyvette]

I have a 1984 with a 700 in it and a 1985 with a 4+3 what do i have to do to put the auto in the 4+3 car?:W

alot of work based on the amount of auto C4s out there.....

Is the 84 a junker that you are just using for parts? would it be cheaper to sell your 4+3 C4 and find a TPI with auto?

it's gonna bolt to the engine no problem, so depending on how many parts you can salvage from elsewhere, such as a crossmember and a driveshaft....find some one that has a tpi auto car and look to see what is different than your 4+3 car, would give a good indication as to what you will need.

things to consider,
computer chip for TPI auto car
crossmember for auto car
kickdown cable and plenum bracket for TPI auto
linkages, cables, and such
center console for auto car

 

[vetteoz]

things to consider,
computer chip for TPI auto car
crossmember for auto car
kickdown cable and plenum bracket for TPI auto
linkages, cables, and such
center console for auto car

Bolt in swap ;obviously need flexplate (153 tooth to suit engine style 1 or 2 pce crank ))
Reuse driveshaft and c-beam ( no trans cross member in C4's )
TV cable should come with trans ; throttle bracket on plenum is the same.
Reverse switch wires need pulling back through floor to attach to auto shifter and 4+3 wiring and relay removed

Computer only controls convertor lockup (TCC) so car will run fine but you will lose fuel economy without the auto chip in computer and TCC hooked up
Some wiring rework need for TCC control
Need the T700 plug and harness back from trans to firewall ; also the TCC switch for brake pedal
TCC uses the same wire to computer that 4+3 does so original hot wire from O/d relay is run inside to brake switch ( or a key on supply found under dash ) , connected to T700 harness and tan / blk wire in same harness connected to same wire on computer
that went to the O/d relay

 

[macgyver]

Yes, I have a donor car that just got totaled last week just bought 1985 4+3 car yesterday.

 

[philbillyvette]

Any particular reason why you don't want to keep it a manual trans???

 

[vetteoz]

Any particular reason why you don't want to keep it a manual trans???

$1500 to rebuild the O/d section of the trans (when it finally goes which it will ) is a good starting point

 

[macgyver]

Thanks Vetteoz

I am going to swap the 4+3 out will I need any of the modules from the 700 car?

 

[vetteoz]

Thanks Vetteoz

I am going to swap the 4+3 out will I need any of the modules from the 700 car?

As you have two complete cars you can either swap the wiring harnesses from the auto car into the stick car ;
or do the wiring rework I listed above.
You will need the chip out of the auto car so just as easy to install the whole auto computer as it has to be removed from its mount to swap the chip anyway

Unless the auto car had 3.07 option rear end ( 2.59 was std ratio ) you will need the VSS unit and speedo gears ( both ) from the 4+3 installed in the T700.
Requires unbolting the tailshaft housing (4 bolts ) on the T700 to swap the drive gear
Easy to do while trans are out

 

[macgyver]

Does it matter that the 84 is a crossfire and the 85 is a tuneport as related to swapping the computer or just the chip?

 

[vetteoz]

Does it matter that the 84 is a crossfire and the 85 is a tuneport as related to swapping the computer or just the chip?

Missed that.
Completely different computers.
You will ultimately need a chip for a auto car to suit what ever engine you are swapping the trans onto

 

[nelson84]

Those 4+3 trans are hard to come by. Why not just sell the stick and buy an auto C4? You can always get more money for the 4+3 than the auto.