Depending on the condition of your current engine you can either swap the d16y8 head and intake manifold onto your block (google mini me swap) or you can swap the entire engine. Head and intake manifold will probably be cheaper than getting the whole engine. Either way you go you will also need the p2p ecu and either the d16y8 wiring harness or modify the y7 harness to work with the y8.
This next part is just my two cents from having experience with doing this. Others are welcome to disagree.
I did this on my old 97 dx civic and drove it for years with the y8 head until a part of the head broke off and it looks like it wedged itself under the cam and tore some stuff up pretty badly. I pulled the old y7 head and ecu out of storage and put em back on it last year.
To be honest when younger me did the y8 swap originally I believed I could feel the difference in power but older me now realizes that was probably just a placebo effect. If im really being honest with myself I probably just thought i could feel the difference because i knew there should be some difference. Even swapping back to the y7 head last year the car basically drove and felt just like it did before. In my opinion you should just keep the y7 if its working fine and if you have any other mechanical issues with the car invest in those first. If everything on the car is mechanically sound but you still really want to invest mucho $$$ to make it faster you should weigh the price of another car vs a motor swap that you can actually feel a difference with such as a GSR b18c1 motor, H22 prelude motor, k series etc.
You might even find that you can just buy a faster car or another honda/integra that has already had a motor swap for the same price range you would otherwise be investing in swapping your motor. Besides the better motor you may even pick up some other nice perks. When i switched from the 97 dx to the 99 ex i regained the y8 motor, and also gained the updated front end, dash, newer style tail lights as well as gaining power steering, air conditioning, bigger brakes, abs, sunroof, cruise control, electric locks, keyless entry, and tweeters. It would have cost more to add that stuff to the dx than what i paid for the new car.
