i have an 89 740 8 valve non turbo. will a 16 valve head fit on my engine? if so, would it be hard?
i have a good car, have never been able to afford a turbo model, but would like more power!

 

You would need to do some extensive research.

The 16 Valve engine has stronger Lower end parts.
The 16 Valve also runs 2 timing belts. One for a Balance shaft.

I really don't know that much about the 16Valve to be able to tell you.