Which bellhousing?

There is no factory bellhousing for that application. If you get a '70 aluminum bellhousing with the large register hole for the 308 bearing trans and the input shaft bearing support that will work. The O/D A833 uses the 308 bearing for the input shaft but the 307 bearing on the mainshaft. I believe the register hole is 4.80" You can also have the O.D. of the stock 5.125 input shaft bearing support ground down to 4.80" hope this helps