So I’m looking into buying a turboed 91 ef hatch. It’s got the d15a1 but it’s got bad compression. I found a cheap d16y8 with vtec and a d16y7. I really wanna do it but have no idea what I need. Also which one would be easier and better in the long run? Any help would be greatly appreciated.

 

There's mountains of information out there on full swaps, adding VTEC heads, etc. Please try to find some of it before asking others to do your research.

https://en.wikipedia.org/wiki/Honda_D_engine#D15A1
What is an ED6 doing with a prior-gen CRX engine in it? Either that car has the most absurd swap or that's not the correct designation. You'll need to know what's actually under the hood to figure out what you'll need to do for another swap.

 

You should know the full story on the blown engine and what all is included with the car (engine management, fuel setup, turbo components, engine internals, etc) and either:
A - plan to rebuild the engine in the car, OR...
B - plan to build one of the engines you are planning to pick up so that it can handle boost, OR...
C - walk away