Like Sheldon posted... There should be only three possibilities (for car/pickup). The L32-34, 10 spline, slightly smaller pinion bearing shaft and slightly shorter (9/16) pinion shaft. Next, 35-up to somewhere in the 38 era, 10 spline, slightly larger pinion bearing shaft and 9/16 longer pinion shaft (compared to L32-34). And, third, same as second except 6 spline. As for driveshafts... yes, L32-34 are hollow, 10 spline. And, 35, 36, and SOME 37, 38 driveshafts are hollow. And, the ones I've seen (few) are 10 spline. Beginning with SOME in 37 & 38, and up, the driveshafts are 6 spline and solid. What Sheldon posted, something strange. It seems like your post does not jive with the possibilities. There is one more possibility that I can think of (and I have done this). Take a 35-up pinion, and modify it to fit a L32-34 rear end. So, you get a pinion that had a shaft for the later bearings, turn it down to fit L32-34 bearings, and also trim off the tips of the pinion gears to fit the L32-34 banjo housing. This modification could be for either 10 or 6 spline.
For your case, I don't know of any way... I'm not aware of bearings that fit the smaller pinion, and also fit the later banjo that accomodates the solid driveshaft. And if you are working with a solid driveshaft, that implies 37-38 era-up, and 6 spline.
Caveat... I see in a catalog that current REPLACEMENT gears are offered with MORE possibilities. This suggests that I can't begin to make a guess as to what you actually have. I see in a Mac's catalog that they offered 3.54, 6 spline, to fit L32-34. This might explain your comment regarding smaller pinion shaft. IF (big IF) this is what you have, and IF they didn't shorten the pinion shaft for L32-34, then you could possibly make it work. I'm assuming L32-34 pinion bearings, and possibly a custom-machined sleeve to make the OD of the bearing compatible. I'm only babbling and speculating here.
