HMMM, with my os 52 I have to use a wood prop or it balances nose heavy. The supertiger is a hunk of lead. I would go with the 0s 61 or a webra speed 61 or a saito 72....something light using the 13x4. You can put one size larger wheels on it and still use the pants.

BTW do not be fooled by hp #'s. My webra speed 61 is about 20% stronger than my supertiger 61. Based on what I have seen on the os 61 it would probably not be much different than the supertiger 90. My os 40 fx is about equal to my supetiger .51.