[ QUOTE ]
WAIT !
Maybe this is the rationale:
Since the 396 was bored +.030 ( actually a 402 ) in 1970,
the HP rating would have been boosted and perhaps that is
why the L/35 disappeared. Still to this day, I wonder why
they made the 402.

It almost seems like a manufacturing
mistake that got away from them. Does anyone know for sure
why the 402 came into existence?
[/ QUOTE ]
There have been many theories over the years, but nothing concrete as far as I know. As for HP going up with the .30 extra, most would say the extra cubes are offset by the lowrise intake manifolds that came on the 70 models. Chevy also added the TCS smog crap in 70, that probably didn't help. Most guys in the day swapped out the lowrise for a 163 or aftermarket unit. Regarding the 402 size, didn't GM have a restriction on engine size in midsize and smallcars of 400 cid...I believe that was lifted in 70,hence the 454 Chevelle was available. Just my thoughts....
wilma