are the d series blocks the same weither vtec or not. i have a d15b, is it basicly a destroked d16a/y/z? the bores are the same right? what about the hieght of the block same or different? if the same does the d15 have a higher rod/stroke ratio stock?

 

The D15 VTEC block is it's own animal, different from the D15 nonVTEC and D16 blocks.