is it alot of work to install bigger valves? Is there machine work needed? where can i get there's valves? if i change them, will i have to do anything else to the engine for it all to work together and not destroy itself?

yes it is more work and the cost of buying fitting and porting head to suit will cost around $1000 BUT WHAT ARE YOU TRYING TO ACHIEVE.if you just want to use twins for no other reason then the sound or to say the car has them ,then just do it.if you want to use them to make power which is what they were designed for then you need to spend money,there is no other option.the valves can be purchased from england at any performance shop or there will be suppliers on this site which can help.i have seen and built many 2lt engines and if you dont follow some of these basic guidelines you will only end up dissapointed with the outcome in my opinion

Well i think mild cam, twins(with smaller chokes), exhaust and see what happens. If im not happy with what I have, I will spend the money and do more. But I dont want to go all out straight away. It is my first engine build and want to learn and progress on time to create something I enjoy.

thanks

regards Hugh

good luck with it all