Conversion driveshaft /6-904-8 3/4

Good morning,

I going to ask if anyone has gone down this route before.
Scenario. I'm building a BB (440) 71 Scamp. While I'm building the engine I will be driving the car with the current setup.
Slant (225) 904 with an 8 3/4 (489,3.55). I can't be the only one that has gone this route. Anyone finish their build and have this driveshaft? Anyone have measurements? If not we'll get under it and measure up and cut the current shaft and use the conversion U-joint.
We'll be pulling the 7 1/4 out in the spring.

Follow the build here
Slow build 71 Scamp 440