Yup, same driveshaft.
The trannies are within 1/8" in length, so no driveshaft mods are required and they take the same slip yoke.
200R4 Overall length 27 3/4”, Face to mount distance 26 7/8”,
TH350 Overall Length 27 5/8” Face to mount distance 20 3/8”,

The only difference is the cross member mounting (about 6" different).
A TH400 cross member needs to be used in place of the TH350 cross member.

Trevor