340 cam in a 318

All I was wanting to know was about people's personal experiences with a 340 cam in a 318, did they notice a performance gain,what other modifications did they do if any when they went with the 340 cam? I know that the 340 cam isn't available anymore so what would be pretty close to it? I've been reading up on the Howard's cam 255* / 261* and it has been recommended by a couple of guys. Is a lunati or a comp xe grind of similar specs worth looking into? Opinions are good, but I'm looking for guys who have had personal experiences with any of these cams.
and each and every guy that actually put a 340 cam in a 318 has spoken - and all responses were positive and a gain of power.