Well I'm using Robart 3" scale wheels threaded/w foam inserts with my Gene Barton retracts units....have the spring loaded struts ( main only)..nose wheel is not spring loaded using 2" robart scale wheels on nose gear (2)..ground clearance is 1 3/4"..am happy with this set up...Will use steel 1/4-20 wing bolts...remember mine is going to weight around 25 Ibs..........yep,I build heavy....Excuse me,while I get back to my 3 engine Italian bomber.....heeeeeeeeyyyyyyyyyyyyy, thats Italian......Kapish?