RE: what is more noticable
either will drop straight in, the cvr-x has a noticeable amount of extra power over the cen .18.
oh u may need to shorten a manifold/header bolt for the cvr-x to work, but thats it.
forgot - if the os is still around $100 bucks (a steal of a price) then get urself one, u wont regret it. how much is the cen motor?