I am waiting till mine arrives (looks like Tuesday hopefully) to decide what engine to use -- I too want to minimize the cutting of the cowl -- from looking at the plans I think the G26 will require alot of cutting and also some added tail weight -- My stearman balances perfect with the G26, but from the looks of the firewall on the Hawk it sets out quite abit farther than the stearman so I do not think I will be going the gas route for the weight and chopping of the cowl. From looking at it I am pretty sure I will be going with the 120 FS engine -- that combination works perfect on my GP Tiger Moth and for those inquisitive minds "Yes" the Moth does hover quite well with that engine -- LOL