I know nothing about BB cars, but isn't L35 a 396? As I stated above, as well as what has been stated from those that have contributed at the referenced link above, in line yokes appears to have been the norm for the BB (396) cars with TH400. What you have stated dovetails perfectly with those observations, i.e. the small block Z28 had offset yokes, the big block L35 had in line yokes.
The other posts at the above link also report that the SB cars had driveshafts with offset yokes (including one for a 307 which also had a torsional damper on it - the addition of a damper for certain applications is shown in the '69 service manual.) For example, why does VIN 124379N581767 (01C build) and 124379N551248 (late Nov '68 build), both base coupes, one with powerglide and one with 3 spd manual have original driveshafts with offset yokes? First car is mine, second car was being scrapped and is the car that I pulled the 327 engine from that currently is in my car. I also kept the driveshaft - still have it. Up to that time, I had assumed that the driveshaft in my car was a manufacturing error. Then lo and behold a second base coupe with the same offset yoke driveshaft.
This has been my question all along - why did GM/Chevy do this in the first place and why did they apply it to a wide variety of SB V8 - far beyond Z28 only.
Based on the contributions of all who have commented on this topic, I would agree that in line yokes seems to have been the norm for 396 with TH400. However, it also appears that the majority (if not all) other applications had offset yokes - a much wider useage than for Z28 only - why? Can't ignore the fact that several base Camaros came with these driveshafts as well.