I thought I would revisit this topic and narrow the analysis to the 1.46 gear ratio SX.
I've talked with Jim at Acme with my data here at 4,500 feet elevation in Utah:
Johnson 402, 4 blade prop LH 1 1/8 shaft", 13X13 stamped on the prop (it's more like 12.5 in diameter) - WOT 6,000; 36 mph
Repaired Acme 425, 3 blade prop LH 1/18" shaft, 13X13 - WOT 5,800; 38.5 mph (runs a little noisier than my 4 blade - could be the repair isn't quite right) I'm going to send it to Acme and they will let me know concerning the repair.
Jim recommemded I try a new Acme 449, 3 blade prop, 13X12.5 - He thought it would give me a little better hole shot than my repaired 425 and possibly increase my mph. He's giving me 30 days to try it then we can talk and see if we can fine tune the performance.
I realize we may be comparing apples and oranges given the elevation differences, but what are you SX owners using and how are they performing?
Thanks,
Brad