There is a Lyman 37FA front sight on eBay right now. The 103C and Lyman 31W were both .310" high; that 37FA will be .370" high. Here is the formula:
Inches error times the sight radius in inches then divide the result by the distance to the target in inches equals the height difference for the sight.
ETA: I am not looking too hard for a Lyman 6W. My gun is reblued plus they are calibrated for 200 and 500 yards! I like my irons @ 50-75 yards!
I went back and did the math that will only get you halfway there assuming the installed front sight is .310" high; you need .120" taller than .310 or .430 high and that probably won't fit with a hood.
