is it possible ? easy ? and what do i need ?

Normally I would say "Have a look in the Technical Documents section; you'll find everything you need," but there is no tech doco for this conversion on EL. I think the NA would be the same as the EA-ED though, so try the tech doco for that. However, I've been compiling info for a similar conversion using an EF (keep in mind that the EF is like the AU and runs coilpack ignition whereas EL has a dizzy). Have a look here: http://www.pertheseries.com/forums/index.php?showtopic=14078

thanks mate was rather helpfull

There are heaps of threads on here concerning fitting an AU motor to E series. You will have no issues fitting an AU motor to EA, EB, ED, EF or EL. You will need to mod the sump to fit and the rest is using the auxillaries that are fitted to your current motor.