Evolution Engines are they good bad or what? I am considering trying them but have not heard much about them.

I think they are very good.  I have no experience with the 60 but have seen good reviews of it.  For the 36 many replace the needle valve but this may be because of weak noses that cause vibration.  The engine is a smooth runner.  Repalcement parts are cheap.  I run them in on a bench but this may not be neccessary.  If you want to get a new needle valve assembly try the OS part #21181902.  This is the 1A,15 needle valve assemby (about 10 bucks).  This screws right into the stock venturi, but use some hi temp form a gasket.  Don't use the large venturi for stunt.  There is a lot of info out there.  Good Luck.