Big thanks goes out to Boxcar. He saw this thread and had pity on me about the retracts. Sold me enough air retracts to keep 3 giant scale warbirds flying at a price I could handle.
Will post flight report when I get these Spring Airs/Robart struts installed. Thanks Ken !!

Jim,, glad your getting faster speeds with the 16x8. I went back to the 17x6 and seem to have better slow speed thrust and control now. I bet we both start getting better runs after a few more gallons of fuel.