Trans Swap Help needed

[SLICK79WGN]

I recently put a 3:73 gear in my wagon and after driving it all week to work. I realized it really needs a OD trans, so I need a little info on what it would take to put in a 200-4r in my 79 Malibu wagon to replace the thm350. I have access to a place with some low mile trans and I know they have a couple of the 200-4r's still in the cars I just need to go pull them, but what do I need to be on the look out for . What I need to know is will my driveshaft work, shifter need replacing I plan on a b&m floor shifter but would like to put that off for now so if I can make my oem shifter work for now that would be great. Next is the cross member I am going to build one for dual exhaust since I have access to a full fab shop. but what are these frame extensions I keep hearing about? Is the OD trans longer or shorter than my current thm350? Last but not least is the lockup function for the torque convertor I would like it to be fully automatic lock up like factory since rarely my wife drives it. Is this something where I can build my own wiring harness or is a kit better if so which one and why? I know this is allot to read guys but thanks in advance for the help

 

[nycutlass]

another idea is to keep everything u have now and just add a gear venders unit and just shortin the driveshaft.

 

[SLICK79WGN]

I thought about that but I would have to mod the floor boards and that is alot more expensive then adding a OD trans

 

[dan2286]

You will need a crossmember for a 2004-R. Your car does not have the mounts on the frame for that trans, so you will need to buy an extension to be able to mount it. The drive shaft will be the same size. I believe the trans cooling lines may need to be routed a little different. I believe the shifter you have now will work, you just won't be able to get it into first gear manually. You will need to get the t.v. cable set up so the trans can live. Depending on what carb you have will determine what you will need. For the lock up, it would be best just to buy a lock up kit that will do it automatically. They are not hard to install, just need to remove the pan and run some wires. Bowtieoverdrives.com has the kits.

I am sure I missed some stuff, but I think I got all of the major things you need to do.

Good luck!

 

[Blake442]

Your driveshaft will work, the trans' are both the same length, but the mount is in a different spot, requiring the different x-member. Check out the G-Force site, they're got the x-member mounting extentions.
Your shifter will work fine, but the shift indicator will read incorrectly.
You'll need the TV cable and bracket... What carb do you run?
The ends of the cooler lines will need to be adjusted some.

 

[SLICK79WGN]

I am running a qjet for now but plan on a edelbrock down the road. As far as the cooler lines what needs adjusted the fitting itself or just re-bent

 

[Bonnewagon]

I wired the lockup to a switch on the dash. That way I could leave it off around town. But I kept the brake pedal switch to disengage it,so if I want to pass on the highway I just tapped the brake and it released.Normally it is a vacuum switch that disengages it.

 

[SLICK79WGN]

hey mark how did you wire it with a relay or did you use a kit?

 

[Bonnewagon]

No, just a toggle switch on the dash. The lockup is accomplished by a valve in the transmission. It is wired to 12v and the computer grounds it. There is a vacuum switch to release lockup when you hit the gas. There is a high-gear-only switch in the transmission too. The brake pedal has a combination brake light/lockup release switch that I retain. There is a connector on the transmission right by the selector shaft, I just wired 12 volts to a fuse,then my switch, into transmission, and out to a ground. By using a dash switch I can run around town with no lockup, and on the highway flip it on for lockup. It's good for about 400 RPM at highway speed, but the overdrive is the biggest help. Mine was a T-350-C but they are pretty much the same.

 

[SLICK79WGN]

sweet thanks mark