1969 Firebird LSx

[Z06vet]

When you say built-in yoke- is it a custom universal joint shaft? If not the yoke can be removed from the shaft. If the 4L60 comes with the yoke, just use it along with your current driveshaft. Bring the driveshaft shop the 4L60 yoke and your current shaft. Ask them where they would like you to take measurements from. They can shorten the shaft, remove the 400 yoke, install the 4L60 yoke, and balance everything. You can sell the T400 and the T400 yoke to re-coupe the money. It cost me $120 to do just what I described above. The old T400 trans + the yoke should be worth quite a bit more than that if its still good. Got a pic of the driveshaft? Scott