RC_FEIND I think the 40 LA would be just fine for the Shrike, Everyone at our club who has Shrike have all said theirs came out nose heavy. Mine has about 3 oz of weight in the tail and that is with the recevier all the way in the back as well. This was not a well thought out project for me I bought 2 Shrikes about this time last year and I gave one to my brother for a Christmas present (he is Chevalier on this forum) and built the the other one over a time span of about 1 month just cause I wanted something to do. I had 2 engines on my work bench to choose from a new ST 40 and a old but still runs well OS 40 FP. If I could have a re-do I would use the 40 FP also I think that the OS 32FX would fly the 40 sized shrike just fine as well. As far as prop size my set up works best with a 10 X 6 its extra thrust makes the hand launch more forgiving, I have used 10 x6 , 9x7, and 9x8 MAS props I found nonly a slight difference in top speed but vertical and rate of climb is better with the 10 x 6.

Oh forgot about the weigh in 4.75lb for the 40 sized one