i have a 98 civic si with a d16y8 that is blown, so my question is my buddy has a good block but its from a d16y7 that is non vtech, so could i use that block with a good d16y8 vtech head?

Yes.

Its called a mini-me. Research before you build or it will break. They are simple to build but certain parts from each engine are needed.

He's actually not doing a mini-me. Mini-me is when you swap from non-vtec head to a vtec head (with d-series engines). He already has a vtec engine/head, he's just swapping blocks. From my knowledge the y7 and y8 blocks/bottom ends, are identical except for the pistons and slight compression difference.

If they are identical then he doesn't have to worry about the timing belt side of things like the Z6/B7 mini-me I helped build. I searched google and this should answer the question: http://www.d-series.org/forums/archi...maybe-not.html