Safebet, this is what I ordered:

http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXNM65

I did it after a suggestion of Edwin on this thread. It has not arrived yet so I cannot tell you how well it fits or works. I will get back to you on that.

As far as brass tubing is concerned, I used an old brass tube from a fuel tank I had. The manual also suggests use a larder diameter brass tubing for the pushrod exits, but since I had none I used by drill. I think the brass tube would do a neater job. I hope somebody else will let you know where to get it, since I'm like 10 billion miles away

I have no experience with the particular engine you mention, I just know that after flying with the .46 LA I know it is on the weak end of the range for this plane. Others suggest even .60 engines.

Serafim