can it be done and if yes what will change

 

People will tell you to search, but of course it's possible.

Look in the FAQ's for 99-00 civic. It's the top thread. You'll find every answer there on it.

 

my v tec looks alittle diff then the y7 i would use a y8 but i have a y7 from my old civic

 

It'll work. The only thing you will have to do is the 3 wires to 2 wires IACV thingy, wire in vtec, and a vtec ecu.

 

The reason your y8 vtec looks different from the y7 is cause the y7 doesnt have vtec. On the y8 head look at the left rear of the head and you should see the vtec selonoid. Yes it will bolt on you just need the ECU, y8 head(complete of course), and you can either wire it up yourself or buy a wiring harness for a y8 and do it like that. Simple and if you do it yourself pretty good bang for your buck.