David:

Might try to find a kit or built model of the Summit 120 on any of the later (pre turnaround) models designed for the 120 4c. Although the 140L might be a lot for it, you might also look at the SL-1. I had an SL-1 (photo below) about 6 years ago with the YS 120 in it and it was one of the best flying planes I ever owned. Put the 140 in it with header from Central hobbies and a muffler from Hatori or a CF muffler from ES Composites.

I used to have a 140L and it was so much stronger than the 140 sport but I lost the plane (current 2 meterish size pattern plane) when the NIMH battery failed. Engine was inverted and the plane hit right side up at about a 45 degree nose down angle. It hit only rock in the area and broke the cylinger off of the case just above the mounting lugs. The 140L is a really nice engine and you might want to keep it in case you find a plane later on.

Just my 2c.

Ed