I have one with a ST G90 and a 13/8 apc. Have a Pitts style muffler also. I've had it *****5 years***** and still a mover. I have a Jett 90 and a 50. Honestly I think its a waste of a real good expensive engine to put in a Shoestring. Put that Jett in a Propjet or something. Anyways, the plane flys really well. I think I have a pic of it in this "my models" icon

I have it mounted sideways and the head was right up against the cowl. So instead of cutting a huge hole as many do, I just dremeled a couple slats for the corners of the head and ahol for the glow plug.