im finishing up my b16a swap and i noticed this hole im not sure what its for but im just wondering... might have been for cable holder thingy

 

nothing really, I have the same poo on my sohc..
if you look all over your block, you'll notice there are lots of similar holes that look like it may bolt to suming...

shave'em of for weight reduction

 

Just a bracket/tab hole.

No real use

 

there all over the place .. just look around ... you'll see them

 

since honda uses the same design on so many cars, i think its easier to incorporate it on everthin gs. ive seen iy used as a ground before and i used it to run a bolt thru a bracket i bought to help keep my vac. lines and harness nice and tidy