I need a top end(d16z6)

I have a d15b7 top end and a d16z6 bottom end. The car will start but wont rev past 4 grand and it takes 10 seconds to get up to 4 grand. The car wont go past 25 mph. So i'm trying to find the d16z6 top end. So if anyone has a top end let me know please.