new to converting, Saw a 25cc and was wondering if it was worth it:

Weedie B1750 Blower-Vac 25cc (not the low emit one)
from the parts manual: 530071456 Assy--Crankcase/Crank

1. the engine is used as a mostly vertical shaft orientation... does that matter? or just mount it right for prop use
2. What is a ballpark nitro size equivalent / prop suggestion
3. Is it worth it in a power to wt consideration

If it is just a generic weedie25, then I'll look up some more threads here to get up to speed on the conversions

thanx for any help ya'll can give
KE