To use an LA engine, you'll have to either put some spacer blocks between the engine mount and firewall, or knock a bit off the cheeks. Power wise it'll work OK for level flight, but take-off, climb and balked landing performance will be marginal. It was designed with the OS .46 AX in mind, which is a bolt-in. I'd recommend using the .46 AX with it - in the long run you'll be happier. Remember the NextStar is a 6.5 lb airplane, even if it has a big wing. While an LA will fly a 5 lb 4-Star just fine, the extra 1-1/2 lbs and additional drag makes a big difference.

Hogflyer