I swapped mine. I used the ST-300 torque converter for now. It's working. Keep in mind you'll have to convert to a cable kickdown rather than electric. I bought a Lokar kickdown cable from Summit. BOP bolt pattern and tailshaft length are all you need to be concerned about as long as it is not a lock-up torque converter. I don't think they were in 1976. I used the speedometer gear out of the ST-300. I had to modify the TH-350 shift cable bracket to put the cable in the right position. If you get into it and have questions feel free to PM. One thing is for sure, you're going to love how it drives with just one more gear!