i need help

[josephkemp]

what do i need to replace my th200c with a th350 transmission and dose anybody know what rear end gears came stock on these i got a 307 under the hood

 

[gto78]

Sorry if I'm misunderstanding but, what model car do you have, what year etc.?

On my grand am it had a stock 301 with a metric 200 transmission. When the transmission started making noise I went to the local transmission shop and they convinced me to replace it with a TH350 and they even put their own version of a shift kit in it. According to them it just bolted right in, and they needed the correct torque converter for a TH350. There's also something you have to do with the downshift cable but I honestly don't remember what it was.

I think if you go to the other section of this forum where they have engine swap combinations, and in the drivetrain section you'll find more information.

JOE

 

[joe_padavano]

what do i need to replace my th200c with a th350 transmission and dose anybody know what rear end gears came stock on these i got a 307 under the hood

The TH350 is a bolt-in replacement for the TH200. This is probably the easiest trans swap there is. The two things you will need to do is to run the kickdown cable (which is different from the throttle valve cable) and to run a vacuum line from manifold vacuum to the modulator on the trans. Oh, and change the speedo gears as necessary.

 

[cdg1984]

You can check what gearing you have with the vin #. I think the cutlass with the 307 had 2.14's or 2.41's.

 

[Blake442]

You can check what gearing you have with the vin #. I think the cutlass with the 307 had 2.14's or 2.41's.

The VIN holds no information about the rear gears.

If your car is an '84-and up, you can look at the RPO label underneath the trunk lid to find the code for the rear gears.
If it is '83-and prior, you'll either have to locate the build sheet if it's still intact, decode the numbers stamped into the rear axle tube, or simply pull the rear cover off and count the teeth.

 

[josephkemp]

are the cross members the same or do i have to change that and i have 86 oldsmobile cutlass supream brougham where would the rear end gear spec's be located at on th car

 

[joe_padavano]

are the cross members the same or do i have to change that

As I said above:

The TH350 is a bolt-in replacement for the TH200. This is probably the easiest trans swap there is. The two things you will need to do is to run the kickdown cable (which is different from the throttle valve cable) and to run a vacuum line from manifold vacuum to the modulator on the trans. Oh, and change the speedo gears as necessary.

Notice that I did not say that you needed a different crossmember.

and i have 86 oldsmobile cutlass supream brougham where would the rear end gear spec's be located at on th car

And as also noted above:

If your car is an '84-and up, you can look at the RPO label underneath the trunk lid to find the code for the rear gears.